Can the USA military be used as a police force domestically? A discussion on a sister Stack Exchange site led me to ask this question. Under what conditions can a branch of the military (excluding the Coast Guard for technical reasons) be used in an active role in law enforcement operations domestically in the United States? By active, I am envisioning active duty soldiers from the Army, Air Force, Navy or Marines breaking down doors and arresting suspects, so above and beyond manning checkpoints and road blocks or logistical operations in support of local law enforcement. Can the President make this decision unilaterally acting under the Insurrection Act, or does he or she need the consent of Congress as specified in 18 U.S. Code § 1385? If it depends, what does it depend on?
The use of the active duty military in a law enforcement role is not unconstitutional but it is prohibited by the posse comitatus act. 18 U.S.C. § 1385 (adopted 1878). The text of the relevant legislation is as follows: 18 U.S.C. § 1385. Use of Army and Air Force as posse comitatus Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army or the Air Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both. Also notable is the following provision within Title 10 of the United States Code (which concerns generally the organization and regulation of the armed forces and Department of Defense): 10 U.S.C. § 375. Restriction on direct participation by military personnel The Secretary of Defense shall prescribe such regulations as may be necessary to ensure that any activity (including the provision of any equipment or facility or the assignment or detail of any personnel) under this chapter does not include or permit direct participation by a member of the Army, Navy, Air Force, or Marine Corps in a search, seizure, arrest, or other similar activity unless participation in such activity by such member is otherwise authorized by law. The act does not apply to the National Guard mobilized at the request of a state governor. In practice, 10 U.S.C. § 375 has more bite because a federal prosecutor can and usually would refrain from prosecuting a crime ordered by his ultimate boss, the President, and there is not legal duty to prosecute every possible crime, but 10 U.S.C. § 375 creates an affirmative duty on the party of the Secretary of Defense that might be enforceable in a civil action.
The general rule is that using force in self-defense is justified if the person using the force reasonably believes it immediately is necessary to prevent the unlawful use of force against themselves or a third party. Deadly force is not generally justified except in response to a reasonable fear of deadly force, or to prevent certain violent crimes (like rape, kidnapping, robbery, etc.) Force is not justified in retaliation. In some states, if you're not at home (or maybe even then), you also have a duty to retreat before you can use deadly force in self-defense. So, for your specific questions: If they hit you once but aren't continuing to hit you, it's illegal to hit them back. You can only use force to defend yourself, not to get even. If someone gets in your face without touching you, you might be allowed to use force, but it depends on the circumstances. You don't have to wait for someone to hit you, but you can't sucker-punch someone because you want more space in a mosh pit. Your use of force needs to be something you reasonably believe to be necessary to stop/prevent their unlawful use of force. It also needs to be proportional to the force you're defending against; you can meet deadly force with deadly force, but shooting someone to stop them from slapping you is murder. Likewise, no one's going to believe that you really thought you had to beat the crap out of someone in order to stop them from slapping you, or that it's in any way proportionate to what they did. Deadly force is not allowed in defense of a person unless you reasonably think deadly force is needed to prevent the unlawful use of deadly force, or to prevent one of a few crimes being committed against them. Depending on the state, it might be presumptively justified if the person is trying to forcibly break into your occupied house, car, or place of business, but that's state-dependent.
This is a hard question, but a good question. The following relates to the issue from the perspective of the USA. You ask "...if the US wants to invade France, can they officially declare war by...", You have to make clear what you mean by "can". If you mean whether or not the US has the physical ability to do this, then of course they do. If you mean whether they are allowed, then this is another question. When you ask whether something is allowed, then you have to make reference to a moral code or a law that determines what is and what isn't allowed (legal). Normally each country will have laws that govern what is and what isn't legal for it's citizens to do. That hard part is how this applies to nations. There are two sides to the question. (1) What are the leaders allowed to do under their own laws, (the domestic laws) (2) what are countries as entities allowed to do? (the international laws) It sounds a bit like you are asking about the second thing. Here treaties govern what is and what isn't "legal". However, usually when someone breaks a law, other entities have the power to enforce that law and decide (judge) whether the person has broken the law. The question is: who decides whether a country has broken a treaty or an international law? And if a law is broken, what exactly can be done about it? This is hard to answer. Consider for example the conflict in Ukraine. Here many will argue that Russia has piratically invaded Ukraine. There should be war between the nations. But Russia denies this and other world powers have done little beyond imposing sanctions. This illustrates how hard it is to deal with this question. One question that comes up is what the purpose of international treaties are if a country can just violate them without much consequence. Pointing out two points about this. (1) If, for example, a president wants to convince his/her own congress that the country should engage in war, then it makes a stronger point if you can show how the country you want to engage has violated international trities. (2) After you have won a war, you might want to prosecute the leaders of the loosing power. Here you will stand stronger if you can make references to some international law that existed before the conflict started. This second point is illustrated in the Nuremberg principles. Here it was exactly stated that "Any person who commits an act which constitutes a crime under international law is responsible therefore and liable to punishment." According to the US constitution "Congress shall have power to ... declare War". That means that historically Congress has the power to decide where to wage war. The War Powers Resolution says, for example, that "The President in every possible instance shall consult with Congress before introducing United States Armed Forces into hostilities ...". Note that this doesn't mean that the US has do formally declare war before going to war. Example: The Iraq War was authorized by Congress, but there never was a formal declaration of war. It is interesting that you ask about the timing for when the declaration should be given. The Japanese wanted to deliver their declaration of war just before the attack on Pearl Harbor. But because of issues with decrypting the message from Japan to the Japanese Embassy, the declaration wasn't delivered until after the attack. Remember also in all of this that the winning party to a conflict, usually decides what was and wasn't legal! One good reference for more on all of this is the report by the Congressional Research Service called "Declarations of War and Authorizations for the Use of Military Force: Historical Background and Legal Implications". Here you can see more on what I have tried (and failed?) to say above.
39 CFR § 232.1(l) provides that: Notwithstanding the provisions of any other law, rule or regulation, no person while on postal property may carry firearms, other dangerous or deadly weapons, or explosives, either openly or concealed, or store the same on postal property, except for official purposes. Police officers on active duty, enforcing the law at the request of post office employees, appear to be discharging &quot;official purposes&quot;.
Presidential power of that type might arise from congressional authorization, where Congress authorizes action when POTUS deems that such-and-such is the case. An example is 8 USC 1182(f), which says Whenever the President finds that the entry of any aliens or of any class of aliens into the United States would be detrimental to the interests of the United States, he may by proclamation, and for such period as he shall deem necessary, suspend the entry of all aliens or any class of aliens as immigrants or nonimmigrants, or impose on the entry of aliens any restrictions he may deem to be appropriate. Explicit constitutional powers are not numerous, but include commanding the armed forces and overseeing execution of national law by appointing and removing executive officers. POTUS is constitutionally the federal official responsible for relations with foreign nations, so he can make treaties (subject to Senate approval) and executive agreements (not subject to approval), can appoint US ambassadors and can receive foreign ambassadors. Executive agreements have the greatest potential for being an avenue for POTUS to act contrary to Congress, but they are limited to agreements pursuant to legislation, treaty and constitutional authority (and, as agreements, are not unilateral). Congress was able to somewhat limit presidential military authority by statutes such as the War Powers Act, and in the policy statement at 50 USC 1541, Congress declares The constitutional powers of the President as Commander-in-Chief to introduce United States Armed Forces into hostilities, or into situations where imminent involvement in hostilities is clearly indicated by the circumstances, are exercised only pursuant to (1) a declaration of war, (2) specific statutory authorization, or (3) a national emergency created by attack upon the United States, its territories or possessions, or its armed forces The law limits the length of engagement of the military, without Congressional approval, but there is no toothful restriction on deploying the military for up to 60 days. 50 USC Ch. 34 more generally addressed "national emergencies", and started by declaring an end to all existing declared emergencies. Other sections of the law require Congress to be notified and emergencies to be published in the Federal Register. An emergency can be terminated by POTUS or by act of Congress, and after 6 months (and every 6 months thereafter), Congress shall meet to discuss the emergency. POTUS must also annually re-declare the emergency to keep it in force. These are procedural requirements, not content requirements. In general, you wold have to go through Title 50 to check for particular powers granted by Congress The International Emergency Economic Powers Act grants powers to POTUS, with the following limit: (a) Any authority granted to the President by section 1702 of this title may be exercised to deal with any unusual and extraordinary threat, which has its source in whole or substantial part outside the United States, to the national security, foreign policy, or economy of the United States, if the President declares a national emergency with respect to such threat. (b) The authorities granted to the President by section 1702 of this title may only be exercised to deal with an unusual and extraordinary threat with respect to which a national emergency has been declared for purposes of this chapter and may not be exercised for any other purpose. Any exercise of such authorities to deal with any new threat shall be based on a new declaration of national emergency which must be with respect to such threat. which appears more limiting than the War Powers Act. There is an extensive list of powers granted under 50 USC 1702, which in that domain could be called "bright" lines. Generally, the lines are only as bright as Congress has painted them.
In the United States, you can always choose to (try to) flee police. If the police subsequently assert that they tried to detain you, then they can choose to charge you with a number of crimes (which vary by jurisdiction). The assertion that you did not (or could not) in fact hear or perceive a lawful order to stop is a defense that you could raise in response to such charges. It is up to the triers of fact to determine whether, given the specifics of the case, they accept that defense.
It is premature to judge the particular case because the facts are not all available. But we can address the general principles. The Model Penal Code 3.04(2)(a) sets out the general principles clearly. A person has the right to self-defense against unlawful force. But, the use of force is not justifiable to resist an arrest which the actor knows is being made by a peace officer, although the arrest is unlawful. But more specifically under (b) The use of deadly force is not justifiable under this Section unless the actor believes that such force is necessary to protect himself against death, serious bodily harm, kidnapping or sexual intercourse compelled by force or threat However, there is a further condition that force is not justifiable if the actor knows that he can avoid the necessity of using such force with complete safety by retreating or by surrendering possession of a thing to a person asserting a claim of right thereto or by complying with a demand that he abstain from any action which he has no duty to take Then finally, §3.05 says that this goes for people using force in defense of others. The short version is that the common law right to resist illegal arrest has been supplanted by a statutory requirement to submit to police authority, for example in California and New York. In Ewumi v. Georgia, defendant was illegally arrested and physically defended himself, which resulted in a battery charge and conviction. The battery charge was overturned because the arrest was illegal ab initio. If one resisting an authorized arrest, where an officer's force is likely to result in unjustifiable great bodily harm, the question is whether a reasonable person would find it necessary to resist in self-defense. It is unusual for the courts to find that to be the case. Minnesota law says that reasonable force may be used upon or toward the person of another without the other's consent when the following circumstances exist or the actor reasonably believes them to exist: (1) when used by a public officer or one assisting a public officer under the public officer's direction: (a) in effecting a lawful arrest Other sections say that a person who is not a public officer may use force to effect an arrest, or, "(3) when used by any person in resisting or aiding another to resist an offense against the person". Being arrested by the police is not an offense, and none of the other justifications for use of force apply.
The question starts with a wrong statement, that international law does not allow the use of force against unarmed border violators. It does. There are human rights involved, and any one border policy may be against international law and conventions, but generally speaking the use of (lethal) force may be allowed. When a person dies, the proper disposition of the body is governed by the laws of the country where the body rests. This can become problematic when the body rests on a border fence, possibly inaccessible from the side on whose territory it is. Once the body is recovered, there may or may not be an autopsy, again according to national law.