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THE RAPID CHANGES OF THE U.S. FOREIGN MILITARY ASSISTANCE TO UKRAINE IN 2019: A NEOCLASSICAL REALISM PERSPECTIVE

In the US fiscal year 2019, Trump and the US Congress agreed to provide foreign military assistance funds approximately $400 million to Ukraine. In its distribution process, Trump procrastinated the release as he decided to halt that in July. Two months later, he changed it and released the assistance. This study seeks to analyze the dynamics of that rapid change policy. In doing so, it employs qualitative research, particularly the process-tracing method as its function to trace the causal mechanism of the research puzzle. By applying Neoclassical Realism provided by Ripsman, Taliaferro, and Lobell, this paper demonstrates some findings: The halt policy is regarding Trump's political endeavor to weaken and outperform his domestic political rival, the Democratic Party. Trump asked the Ukrainian counterpart to investigate Joe Biden's corruption and reverted Russia hack scandal in the last US presidential election in exchange for the release of military assistance. However, the policy was hampered by some domestic elements, (1) some of the Foreign Policy Executive thought the halt policy was not following the US national security, hence they acted as whistleblowers issuing Trump personal interest in the issue to gain wider public awareness; (2) US Strategic Culture, a perception that shapes Russia as among US enemy. Thus, that halt policy is perceived against US collective value; (3) US check and balance system; (4) Trump consideration that the halt policy can jeopardize his position as president in the next election. These factors contribute to the release of assistance.


INTRODUCTION
Foreign military assistance by definition is the transfer of weaponry, equipment, funds, training, or leadership to recipient military force (Mott, 2002). However, what does it mean for states to do such cordiality manner whereas foreign military assistance can cause them to spend more on unnecessary costs and energy. Let alone, as the assistance turn the recipient states gain more power, the variable of defection in the recipient state, as it is well understood in international politics, can result in the assistance to become detrimental for the donor state.
Some prominent scholars argue that the rationale of states to provide military assistance to the others, despite substantial costs, is because they aspire something larger than the incurred cost. To be exact, that includes certain political objectives to be pursued and contextualized. Among other explanations, studies portray that it is frequently directed to create balancing behavior, protect or oust the regime, preserve or overthrow hegemony, increase state security or power, disseminate democratic values, conduct ways for conflict prevention, or shape a new amity pattern (Waltz, 1979;Walt, 1987;David, 1991;Geis, Brock, & Müller, 2006;Cottey & Foster, 2004;Mearsheimer, 2001).
Viewed from historical perspectives, military assistance in practice has occurred for a long time, even longer than the emergence of the nation-state model itself. The earliest form relating to military assistance was the hiring of foreign military advisors and mercenaries. Political entities at that time often asked for help from outside military experts who could organize mercenaries and hooked the exenemy forces up in the hope of increasing their war capability (Stoker, 2007).
In the meantime, the configuration of contemporary military assistance is more diverse and is no longer limited to the advisory functions. Some of the contemporary forms include the deployment of military as peacekeeping force under the United Nations (UN) mandate, arms sale, weapons grants, up to capacity building programs. As Cottey and Foster (Cottey & Foster, 2004) noted, the varied military assistance configuration is based on the growing awareness and strategic rationale of states (especially those in Western) that militaristic issues can not merely be beneficial for the sake of defense, deterrence, compellence, or swaggering (Art, 2017), but also has widely been seen as a security and foreign policy tool.
While in practice this topic gains traction to many states, scholarly works concerning comprehending the state's strategic goals will become noteworthy to deepen and enrich our understanding of this topic. Against this backdrop, this article aims to explain it in the case of the US-Ukraine in 2019 as a research focus. This is chosen due to the recent development in US foreign policy under President Trump that demonstrated a batch of discrepancy with the US traditional role in foreign and security policy, making it possible for further theoretical debate and development.
The United States is one of the states with very long military assistance experience either as a recipient during the American Revolutionary War when George Washington was assisted by Baron Friedrich Wilhelm von Steuben, ex-Prussian military, or as a donor with several programs, such as International  (Cottey & Foster, 2004;Stoker, 2007).
To put Ukraine in this context, the US has long been involved in carrying out the agenda of security cooperation since Ukraine gained independence from the Soviet Union back in 1991.
The first important stage encouraging security relations between the two states was the signing of the Budapest Memorandum on Security Assurance between the US, Russia, Britain in 1994 in which the three parties agreed to maintain security assurances against threats or use of force and against the territorial integrity or political independence in exchange for disarming Ukraine nuclear weapons which at that time become the third-largest nuclear weapon stockpile.
Military relations are not only built on bilateral based ties, but also through multilateral engagement such as NATO (North Atlantic Treaty Organization). Since the dissolution of the Soviets, this organization has tried to forge partnerships with states in the Euro-Atlantic Area through the program called the Partnership for Peace (PfP). Through this intended for the trust-building program, Ukraine can establish military cooperation with the U.S and its allies in various matters, including joint training, defense sector reform, planning and response to non-traditional security issues such as disaster, environmental issues, to democratization within the framework of civil-military relations (NATO, 2017).
The enhancement of defense relations has encouraged Ukraine's desire to become a NATO member state in 2008. Although it was not realized due to changes in the domestic political landscape, the Russian invasion of eastern Ukraine has once again stimulated Ukraine's desire to become a part of the NATO alliance (Bandow, 2014).
The conflict befallen Ukraine in recent years has caused the contribution of the United States so much awaited by the Ukrainian side as part of counterweight to the annexation of Crimea and other territories by the Russian military and pro-Russian groups in the south and east of Ukraine. Meanwhile, for the United States and its allies, besides their balancing rationale, normatively, their presence in Ukraine is justified too as Russia's militarization is considered to violate Ukraine's sovereignty as stated in Budapest agreement back in 1994. For this reason, the US and its allies imposed economic sanctions on individuals and companies affiliated in supporting Russian annexation (U.S. Department of The Treasury, 2014). In return, Russia also blacklisted several parties that politically associated with its rival so that they are unable to enter Russian territory (Gutterman, 2014). As a result, this tit-for-tat does not make tension de-escalated, instead it intensifies the militarization surrounding the Sea of Azov and the Black Sea (Vasilyeva, 2018).
Things are a little bit different as Donald Trump won the U.S presidential election back in November 2016. He has frequently demonstrated conflicting stances in several US Foreign policy behavior at a global level (Patrick, 2019;Acharya, 2018;Bennet, 2018). For example, Trump called for keeping its substantial military in the Middle East as his sign to launch more military operations in the future, shortly after he broke his commitment away, deciding to withdraw thousands of US military back home (Hennigan, 2018 pragmatic; up until Jacsonian-populism (Dombrowski & Reich, 2018). But the inquiry to explain Trump's rationale to halt and release military assistance, particularly and dyadically, to Ukraine remain understudied. As such, this study seeks to disentangle that anomaly decision by stating the following research puzzle: Why did the United States under the Trump administration demonstrate rapid changes from terminating military assistance in July to the release in September 2019 about the US military assistance to Ukraine?

ANALYTICAL FRAMEWORK
To answer the research puzzle above, this paper employs the Neoclassical Realism research program developed by Ripsman, Taliafero, and Lobell (Ripsman, N., Taliaferro & Lobell, 2016) as theoretical guidance.
Considering foreign military assistance as a part of wider foreign policy or state's international political agenda, in the first place it is necessary to clarify where the state's foreign policy response derives. Two prominent approaches in international relations demonstrate intense dissimilarity. Those scholars in structural realism believe in the systemic stimuli (international pressure) where states exercise foreign policy as a response to the other actor behavior in the anarchic international system. Meanwhile, those innenpolitik scholars in liberal tradition argue that it is bottom-up made. Given its assumption that state is not unitary or independent actors, the theory believes that foreign policy and state's international politics is obtained as the aggregate preferences of the dominant societal coalition to explain state behavior (Ripsman, N., Taliaferro & Lobell, 2016).
Neoclassical Realism places the two approaches above in the criticizing position. Innenpolitik is criticized for downplaying two insights. First, due to blindfolding the relative distribution of material power. Second, by getting rid of the central role of the state's foreign policy executive such as president, prime minister, key cabinet members, advisors charged with the conduct of foreign and defense policies.
While its criticism for Structural Realism, despite their similarity in the philosophical foundation, lies on the balance of power expectation explaining that state will automatically balance against the threats that state face in the international arena. For Neoclassical Realism, seeing the balance of power behavior as a state of automatic affairs will be too reckless. Once deciding foreign policy, states face complex decisionmaking environments. Their foreign behavior can become an anomaly in certain circumstances. As such they cannot always and automatically follow those structural realism proponent expectations to choose the most optimal policy response to the external environment such as balancing strategy. On the other hand, states must face a series of alternative policies that can navigate systemic constraints and domestic political imperatives that Structural Realism thinks it is not significant.
To outsmart the deficiencies in Structural Realism and Innenpolitik theorist, Neoclassical Realists try to provide logical explanations to explain international politics in a series of variables, ranging from (1) independent variable, systemic stimuli that have causal importance; (2) intervening variable, domestic political factors affecting the process of perception, decision making, and its implementation; to (3) dependent variable, the policy choices made by states influenced by the international outcome and structural change in the international system (see figure below) (Ripsman, N., Taliaferro & Lobell, 2016).
To understand systemic stimuli as the independent variable, defining what constitutes the international system -the political environment within which states interact should be clear in the first place.
The international system in Neoclassical Realism conception is regarded as an interstate system within which those who are known as great powers become the most politically consequential actors given their relative power. Those in the system see international politics as a never-ending struggle for power and influence in the world that is bound to resource and having uncertainty about each other intention and capability. Factors affecting the ability and the willingness of units to interact, and determine what types of levels of interaction are both possible and desired can be seen through what is called "Structural modifiers" which includes geography, technological diffusion, and offense-defense balance in military technology. The next issue in the systemic variable should include what condition explains the international system within the meaning of the strategic environment and its clarity level. The former is defined as the magnitude and imminence of threats and opportunity the state face. The more imminent the threats and opportunities, the more dangerous the threats, making it a restrictive strategic environment. The state tends to balance in that environment. On the other hand, the more remote the opportunities and threats, the more permissive the strategic environment is. Thus, the state decides whether to balance or not will depend on domestic political circumstances. Meanwhile, the letter (clarity level) is defined as the degree to which the international system provides information about the nature of threats and opportunities, their time frame, and the optimal policy response to them. Those socalled clear threats are states possessing three attributes: having revisionism or hostile other states territory, having a great capacity in military and economy, and a sense of imminence that is the capability to inflict in the short order (Gaddis, 1982;Walt, 1987).
Shifted to intervening variables, the theory provides four categories to explain various constraints for the central actor (state) that can affect how the state responds to systemic or external stimuli.
First, leader images. This variable was concerned with the beliefs of individuals who officiate at the helm of the state. They are named Foreign Policy Executives (FPE) consisting of a president, prime minister, dictator, key cabinet members, ministers, and advisors charged with the conduct of foreign and defense policies. For the neoclassical realist, investigating the character and psychological make-up of the political leader will be critical.
Every FPE has core values, beliefs, and images guiding their interaction with others. Once formed, they act as the FPE cognitive filters that inform how leaders proceed with the information. All incoming information on international politics passes through these cognitive filters from which external stimuli are biased and personalized depending on the content of their images.
Second is strategic culture. Snyder defined strategic culture as the total of ideas, conditioned emotional responses, and patterns of habitual behavior that members of a national strategic community have acquired through instruction or imitation and share (Snyder, 1977). Meanwhile, Longhurst defined strategic culture as "a distinctive body of beliefs, attitudes, and practices regarding the use of force, which are held by a collective (usually a nation) and arise gradually over time, through a unique protracted historical process" (Longhurst, 2004). Here, culture is not defined in the conventional sense, rather suggest a distinctive approach toward strategy the state do derive from its history, geography, political culture, up to the aggregation of the attitudes and patterns of behavior of the most influential voices; these maybe, depending on the nation, the political elite, the military establishment and/or public opinion (Booth, 1990). Through socialization and institutionalization, the collective assumptions and expectations become entrenched and constrain a state's behavior and freedom of action by defining what is acceptable and unacceptable strategic choices.
The third is state-society relations. This variable encourages the researcher to investigate the character of interaction between the central institution of the state and various societal and economic groups. Should the relations be in harmony, the ability of the state to mobilize, extract, and harness national power can be much more effective and policymaking is consequently consistent with the structural realism model. In contrast, if harmony does not occur, the policymaking process would be extensive and the result of the policy would satisfy domestic interest rather than exclusively international consideration.
Fourth, domestic institutions. This variable seeks to understand the institutional structure of the state, established by constitutional provisions that determine who can contribute to the policy formation, at what stage of the policy process, and who can act as veto players to block or reshape governmental policies. Therefore, this variable seeks to investigate, to say the least, the degree to which power is concentrated in executivelegislative relations, party system, electoral system. For those adjusting democracy in substantial in which check and balance applied, the foreign policy decision making can be more complicated to the extent that they should hold extensive consultation with those opposition forces as their competitor over policies. As this occurs, those who govern should compromise or form a winning coalition to ensure a policy adoption (Ripsman, N., Taliaferro & Lobell, 2016).
Turned into a dependent variable, the theory says it will vary depending on the time frame and receive influence within intervening variables. In the sort time, leader images matter most but as the decision time increase, individual leaders' control over policy decrease as many other actors such as legislatures, interest groups until society at large have the opportunity to contribute for devising policy solutions.
Strategic culture affects both short-and long-term decision making. As a crisis happen, and a quick decision is expected, strategic culture may guide or constrain the choice of the use of force and foreign policymaking.
In the longer term, those FPE draft plans for grand strategic adjustment. In this term, the leader is less likely to select policy options that contradict domestic value. The reason is, inter alia, to hold the leader's power if the decision can generate significant political opposition (Ripsman, N., Taliaferro & Lobell, 2016). As a matter of this fact, state-society and domestic institution have little influence on short term policy responses but is significant for longer range planning due to a quick response decision on foreign policy place disproportionate power in the hand of leader shaping national response.
However dependent variable and how the intervening variable operates is influenced by the independent variable in conditions that international system demonstrates four conditions.
First, a restrictive model and high clarity. In it, FPE cannot have significant bargaining with domestic groups so domestic institutions and state-society cannot affect the policy. Instead what is most relevant in this situation would be strategic culture and leader image.
While in a permissive strategic environment where states have no pressing threats and waning opportunities with high clarity, domestic institutions, and statesociety relations become more prominent. As the time protracted, FPE will face difficulty in mobilizing domestic support. That situation will make the leader image less relevant.
As the clarity is the low and strategic environment is permissive, four clusters in the intervening variable can be relevant, policy priority is indeterminate due to the absence of a pressing threat.
And in a situation filled by low clarity and restrictive, leader image and strategic culture can again become the most relevant due to the degree of threats and waning opportunity will encourage the national leader to ignore societal demand on strategic grounds.

METHODS AND PROCEDURES
This paper employs qualitative research, particularly the process-tracing method as the author considers it as the most representative method to trace and answer the causal mechanism of the research puzzles -Trump foreign military policy shift to Ukraine mentioned in the previous sections.
As Derek Beach (Beach & Pedersen, 2013) stated, process tracing is a method aimed at gaining a greater understanding of the causal mechanism from which the outcome is produced. This causal mechanism is defined as a complex system, which produces an outcome by the interaction of several parts (Beach & Pedersen, 2013). To seek that complex system, Neoclassical Realism with its arrangement of variables explained in the previous section helps compile what variables need to be investigated, linking cause or set of causes to the outcome.
The focus of author data gathering is collected through document-based research. In doing so, the author will investigate relevant topics in explaining the halt policy in July and the release policy by investigating two kinds of document: (1) primary documents, consisting of those undergoing individuals who have a direct connection with the topics and original or official documents; (2) secondary documents, consisting of media reports, books, and scholarly articles. In assuring the validity of the collected data, triangulation strategy by cross-checking data from multiple sources so as a balanced situation occurs will be employed during the inquiry process.

RESULT AND DISCUSSION
This section discusses the operationalization of the analytical framework of the neoclassical realism model proposed by Ripsman, Taliaferro, and Lobell (Ripsman, N., Taliaferro & Lobell, 2016). In doing so, the first subsection will portray systemic stimuli as the independent variable. It will highlight the distribution of material power in Eastern Europe, the offense-defense balance between Russia and Ukraine, and the US military role in the region and supporting data to comprehend whether the nature of the strategic environment is restrictive or permissive and whether the systemic clarity is high or low. Then, in the next section, it will trace the perception, decision-making process, and policy implementation of US foreign military assistance to Ukraine. Intervening variables such as leader images, strategic culture, state-society, and domestic institutions will not be presented in a separate section, rather they will be used more loosely in each section as their explanation contributes to the issue.

Shedding light on how the United States respond to systemic stimuli in Eastern Europe strategic environment
In Eastern Europe, countries are hardly possible to exercise external balance against Russia unless they, particularly Ukraine, seek it by becoming NATO member states. It is so because there is a vast discrepancy in military balance which shows Russia superiority (see figure 1.) (SIPRI, 2020). Once they attempt to do so, Russia's reaction would strictly be in disagreement and then deploy its military to thwart their political eagerness. It has happened at least twice in the last fifteen years, first in Georgia (2008) and second in Ukraine (2014-present) which both states previously aspired to be out of Russia sphere of interest and turn around toward NATO or the West in general.
For the United States and its allies, securing their interest in Eastern Europe particularly Ukraine is geopolitically important to make a sure balance of power indwell. And for the United States, in particular, it seems that its historical competition during the Cold War and the agenda of liberal idealism have shaped its strategic culture to have deep distrust to Russia despite the war has ended and slightly different view of the current president toward Russia (Mahnken, 2006;Hudak, 2019). In 1994, US National Security Advisor, Zbigniew Brzezinski wrote an article in Foreign Affairs stating that, in essence, Ukraine position is geopolitically significant for United States interest in Europe. The stronger Ukraine, the higher probability of Russia regional dominance to be thwarted. On the contrary, in case Ukraine is on a brink of disaster, the crisis may be exploited to promote the breakup of Ukraine as an independent state or the reintegration of it to Russia-dominated framework. As this happens, Russia shall reemerge as an empire. Accordingly, the United States needs to engage the Ukrainian government through the substantial economy and security Ukraine assistance while the place Russia remains in a potential threat despite the cold war ended (Brzezinski, 1994). After the article was published, several initiatives aiming at political assurance have been popped up by the United States, commenced by the signing of Budapest Memorandum 1994 to the current initiative such as Ukrainian Security Assistance Initiative (Welt, 2019).
Center for International Policy, an organization aimed at tracking US security sector assistance, demonstrated in detail how far the U.S security assistance to Ukraine is. Its data show that along with Russia annexation in 2014, the U.S assistance has grown in number compared to its aid from the 2000-2013 fiscal year which never exceeds 100 million dollars (Center for International Policy, 2020a). Based on the same dataset from 2014 to 2019, US security assistance seemed to focus on, but not limited to, five programs namely: (1)  It is difficult not to associate that rapid upsurge for the last five years with Russia military aggression in southern and eastern Ukraine within which is read by the US and its European ally as an existential threat, let alone that they are in the imminent geography.
Besides, the other two trends support the argument that the United States and Russia negatively see one another. First is demonstrated by recent public opinion and second by military relations.
For the US public, as Gallup polls told, Russia is among the top four to be perceived as US greatest enemy in conjunction with other countries that politically closed to it such as China, North Korea, and Iran. As a matter of fact, for the last four years, it becomes the first place twice in polls, amounts to 18% in 2015, and 32% in 2019, making it as so-called the US chief enemy (Gallup, 2020). Besides, the survey in 2019 revealed that the majority of Americans (52%) perceived that Russia military power poses a threat to U.S vital interests. That number is tripled compared to the survey with the same question back in 2004.
In military and strategic relations, despite demonstrating cooperative measures in non-traditional issues and other confidence-building measures such as NATO-Russia council or Russia participation in Partnership for Peace program, Russia and the US relation remain stubborn. It is noted that before Russia annexation to Ukraine, both powers had a tense confrontation on several cases including Kosovo War (1999), Georgia War (2008), and US Plan to build European Missile Interception in Poland and a radar installation in Czech near Russia border (2008). And now it is going on in Crimea and Donbas, Ukraine (Keaney, 2020;BBC News, 2000 Association Agreement which covers multifaceted areas including trade, visafree, infrastructure, up until foreign and security policy from which Ukraine would intensify dialogue under Common Security and Defense Policy. On the contrary, he opted to have closer ties with Russia, which afterward dragged him out of the office and fled to Russia (EUR-Lex, 2020;BBC News, 2014).
However, those large-scale Ukrainian protests did not represent a single, solid voice of the population. Ukrainian is segregated into two factions: those favoring EU and those favoring Russia located in eastern and southern of state. This led Russia various forms of intervention to expand easier to that area.
What suffered more for Ukrainian security ahead of Russia annexation was that it had no sufficient military capacity to push backward Russia military operation (SIPRI, 2015;Davis, 2016). It is likely, to cite Robert Jervis offense-defense balance theory (Jervis, 2017), for Russia the time has come to offense since it has an advantage in technological and offensive weapons than its neighbor rival and even more there is no guarantee to stay silent while its buffer zone to Europe can, in the longer term, threaten its security. Later, if Putin did not lie when saying "Russians and Ukrainians are one people...one nation" in an interview with Oliver Stone, it may be assumed that what Russia strategic goal is not only the control over Crimea and Donbas but Ukraine territory as a whole (Associated Press News, 2017).  (Davis, 2016) The Ukraine conflict, economicmilitary power balances and economic sanctions, Post-Communist Economies, 28:2, 167-198, DOI: 10.1080/14631377.2016 A month after the large-scale protest in Kiev, Crimean, Russian speaking population, held a referendum on March 16. It resulted in the majority of the population wanted to join Russia despite most of the international community refused to recognize that referendum. Leader of Crimea and Putin signed a treaty accepting Crimea and the city of Sevastopol as part of Russia territory. A couple of weeks before, soldiers with green army uniforms carrying Russia military equipment: wearing flak jackets, holding rocket-propelled grenade launchers, and sniper rifles blockaded Simferopol International Airport, a seized government building. Russia called them as self-defense groups while his rival accused it as a part of Russian Invaders (Shevchenko, 2014;Siddique, McCarthy, & Yuhas, 2014).
As the Crimea annexation was considered successful, Russia subsequently increased its military presence in the region by deploying more than 30,000 troops, bringing S-400 surface to air missile system and other advanced weaponry, and began to set up military task force there focusing on, to say the least, two things. First, securing some areas of Arabat Spit and Kherson Oblast which housed a gas distribution center. Second, control over the strait of Kerch located between Sea of Azov and the Black Sea from which Russia fired and seized two Ukrainian artillery boat and a tugboat in 2018 (Baker & Kramer, 2014;BBC News, 2018;Welt, 2019).
Donbas -refer to Donetsk and Luhansk located in eastern Ukraine is the second flashpoint where armed conflict between Russia and Ukraine is exercised. Several cities were forcibly occupied by separatists associated with Russia the so-called Donetsk People's Republic and Luhansk People's Republic. To restore state control, Ukraine Force and volunteers were there but suffered major defeats in three battles which Russia force reportedly joined in (1) Ilovaisk from August to September 2014; (2) Donetsk Airport from September 2014 to January 2015; (3) Debaltseve from January to February 2015 (Welt, 2019).
However, despite elements of militia demonstrated resistance against Putin and Russian backed rebels, these groups can also pose a serious threat to the future government of Ukraine. Azov Batallion may receive government support from Minister of the Interior, but they are known as neo-Nazi sympathies; Right Sector operates independently as they refused to register with the government; Dnipro, about its loyalty for the country, is doubtful since they are oligarch funded. But again, for this short time, Ukrainian only has few options (Taub, 2015;Cohen, 2018).
As Ukraine repeatedly ask western countries to sell or give more lethal equipment that it lacks, such as electronic weapon systems to protect aircraft against SAM, artillery-locating radar, radio, UAV, up until body armor, United States under Obama administration and its NATO allies seemed to take steps carefully whether they need to arm Ukraine or not. As a result, they only focus on non-lethal weapon supply considering the following conditions: 1. The possibility of escalating the conflict with Russia. 2. The need to maintain the conditions for a successful diplomatic process based on economic and political sanctions on Russia, economic aid to Ukraine, and negotiations.
3. That the Ukrainian armed forces were in too much disarray to absorb large numbers of new weapons. 4. That delivery would not change the balance in access to weapons since Russia could increase deliveries to the rebels (SIPRI, 2015). Under Trump administration, the US military assistance seemed to be shifted from the Obama approaches. Trump appeared to be bolder in providing lethal weapons to Ukraine. Throughout 2017 he was actively reviewing the question of lethal assistance. As a result, in 2018 the Department of State agreed to provide foreign military sales of 210 Javelin portable anti-tank missiles, 37 launchers, and associated equipment (Martinez, 2019). And in June 2019, Department of Defense through Security Assistance Initiative FY 2019 stated that it would allocate $250 million to enhance Ukrainian maritime awareness, provide sniper rifles, rocket-propelled grenade launchers, counter artillery radar and for Ukraine's Land and Special Forces; mobile command and control, electronic warfare detection and secure communications; military mobility; night vision; and, military medical treatment (Welt, 2019).

In the process of halting and releasing the foreign military assistance decision
Despite posing a stronger form of external balancing strategy against Russia annexation, US military assistance to Ukraine in 2019 brought a series of a different situation. In its process, rapid shift policy was exhibited when the US decided to halt military assistance in July, and shortly after, released it in September. Two factors are intertwined. First, Trump's interest was behind the frozen policy, while US domestic institution structure and strategic culture allowed Trump's interest to be cracked and challenged.
In democratic states such as the United States, those who eager to become president should compete through the election and when he or she is elected, he or she is given the second chance to return to the office as the United States constitution permit two-term limits. This second chance is sought too by Trump who will compete in the next presidential race in late 2020. But his first three years in office seems did not show a great number of approvals as many polls tracing public opinion demonstrated 'majority disapprove' with the current president job. What he needed to do politically was to revamp the situation by lessening his rival, Democrat to achieve more public support. To do so, he attempted to reverse the public narrative of his scandal with Russia and seek the deceitful possibility of a Democrat presidency candidate and Ukraine is seen as a perfect object to process his plan.
In February 2019, Congress authorized the aid to Ukraine in the fiscal budget 2019 within which the Department of Defense would provide 250 million dollars for military aid and the Department of State would provide $141,5. Million for other purposes.
On June 18, DoD released news regarding equipment and military services that the US would provide to Ukraine (US Dept of Defense, 2019).
A month later, it seemed that the Office of Management and Budget (OMB) placed a hold military aid package under the order from Trump and no one at the office knew the exact time of the hold duration would be lifted meanwhile the fiscal year would end in the end of September (Welna, 2019). This act could be seen as violating the 1974 Impoundment Control Act due to the president's unilateral movement, whereas it has to tell or notify Congress before the decision (Gringlas & Pao, 2019). At the end of July, Trump had a call with Ukrainian President, Zelenskiy and asked him a favor to probe his leading domestic political rival Joe Biden and his son Hunter Biden activities in Ukraine and disproved the claim that Russia hacked the computer server of Democratic National Committee (Welna, 2019).
Trump's decision to halt the military assistance seemed disappointing to many sides, particularly some military and intelligence officers. It also becomes a serious national concern in the United States after a whistleblower filed a complaint of what happened about Ukraine-US relation to Richard Burr and Adam Schiff, chair of the Senate Intelligence Committee on August 12, and publicly gained a wider audience as mainstream media such as Politico (28 August) or The Washington Post (5 September) reported the issue, marking clearer that this assistance could not be aside from the US presidential election preparation that will be held in 2020 (CNN, 2019).
The complaint, as went to be a public consumption, disclosed new important elucidation that Trump tried to solicit Ukraine to interfere with the US presidential election in the upcoming 2020. Trump and his team saw that there would be a political advantage to raise the Biden issue in Ukraine about his energy company in that country, Burisma Holdings.
In the beginning, Shokin, Ukraine Prosecutor General 2015-2016, probed Biden Burisma company activities but stopped in the middle of the road as Biden allegedly ask Ukraine President Porosenko to sack Shokin so that he could not tar Biden's reputation. Shokin position was succeeded by Lutsenko. Instead of stopping the investigation, the newly elected prosecutor seemed to continue his predecessor's work after Trump and his team endorsement.
In 2019, Giuliani, Trump's lawyer, with the help of Shokin, corresponded with Lutsenko in New York (late January) and Warsaw (mid-February) from which he was allegedly willing to help Trump (Unian, 2019). Due to that conversation, in late March Lutsenko made a series of allegations against Ukrainian officials and current and former US officials who politically associate with Biden.
But the situation was harder in Trump and his team perspective when there was a domestic political transition in Ukraine. A Ukrainian presidential candidate, Zelensky, who promised to replace Lutsenko from his office, won the election on April 21, 2019. For Trump's point of view, this reality would complicate his interest. He needed to find a new strategy to keep Lutsenko still at his office. Meanwhile, Zelenskyy, per se, besides his efforts to subdue corruption, was encouraged to make sure American military assistantships went in a good manner as one of his short-term priorities to overcome the Ukraine-Russia crisis in his eastern and southern territory. What Trump thought a solution for this matter is best drawn by quid pro quo frameworks, a Latin phrase meaning a favor for a favor. He wanted Ukrainian to do what he commands, so the foreign military assistance that Ukraine urgently needs would be channeled.
Shortly after the Zelenskyy winning announcement on April 21, Trump indeed had a brief call with Zelensky to congratulate and invite him to the White House. However, the meeting itself was never been realized until the end of September despite the requests were offered several times by the Ukrainian side.
Trump was not willing to meet Zelenskyy before he complies with Trump's demands but Zelensky and his team perceived that Trump's demands were way too risky to do. That was depicted by several meetings between Trump aides and Ukrainian president delegations during May and June that reached nothing. The peak was when Trump officially decided to withhold that military assistance by July 12, turning the coercion into a new different level than before.
However, a report made by the US House of Representatives titled 'The Trump-Ukraine Impeachment Inquiry" demonstrated a more complex situation within US officials. During a series of policy meetings involving senior officials and relevant actors associated with this matter, many officials instead supported the release of the funding arguing that supporting Ukraine was in the national security interest of the United States. On the contrary, if the president continued to withhold the assistance, Trump, they concerned, would face legality issues with the Congress. It turned out that the decision was also problematic in the United States and did not reach a compromise as soon as the decision passed (US House of Representatives, 2019).
As time goes by, policy options for Trump were increasingly limited. House Representatives, after the whistleblower complaint and media reports on the military assistance withheld, turned to be a fierce barrier for the executive to continue such policy. And that Trump seemed to end the halt by 11 September. He picked corruption concern as his rationale to withheld such assistance and denied all statements linking with his political interest as his exit plan but it did not end up the House Representative investigation to impeach him (Rupar, 2019).

CONCLUSION
To conclude, the US military assistance policy to Ukraine in 2019 demonstrating twist and turn circumstances on the US side is due to the internal collision in a growing unusual demand to benefit Trump's political interest regarding presidential race in its process against the US traditional values and institutional mechanism rather than a decision based strategic calculation, as this move eventually endanger Trump position to keep in power.
For Trump, this decision is necessary to outperform his rival candidates in the Democratic Party as he knew his position was at risk since his approval rating conducted by several survey agencies was always disappointing. Even worse the next election is near to come. Incorporating that Ukrainian prosecutor to investigate Biden in his third year would politically be influential to turn things around.
As the initial step, Trump likely got it. Nevertheless, he failed to convince some officials in the military and intelligence office that his decision is fully part of US national security and interest. As a result, a whistleblower who is allegedly part of the intelligence officer anonymously leaked the issue to the House of Representatives, and as time goes by scattered to media.
What whistleblower did is in part associated with US strategic culture. US public and military consistently show distrust to Russia rather than other states as some polls revealed. Thus, terminating foreign military assistance to Ukraine will mean strengthening Russia's power, the US chief of the enemy.
For Trump to be elected, implementing a policy that opposite with public perception can jeopardize his position and degrade his second chance to win presidential elections. His choice, by all means, was increasingly restricted as time goes by. The rational decision thus is to release foreign military assistance to Ukraine and put some issues to obscure his political interest.
Hence, factors contribute to the rapid changes in the US foreign military assistance to Ukraine are influenced by Trump images or personal political interest, the internal conflict in FPE, strategic culture, and domestic institution. Theoretically speaking, despite Structural Realism prediction on the balance of power might be correct, but Neoclassical Realism provides a better framework and mechanism to arrive at that outcome policy.