provide liquidity to federal contractors and their suppliers. We in turn advanced payments across our supplier base to help maintain the health and liquidity of our supply chain. Outside of the United States, other governments have established various government workforce programs, which can support business continuity for our foreign operations. We continue to assess the benefits and limitations of the actions taken by the United States and other governments. See Note A to the Consolidated Financial Statements in Item 8 for additional information about our use of estimates and other uncertainties. Our U.S. government business experienced some disruption from the COVID-19 pandemic, including reduced activities due to select customer site closures and limited access to some customer sites, travel restrictions, slowdowns in the provision of materials from suppliers, and lower man-hours at some manufacturing sites. Internationally, while government actions shut down some of our facilities in the second quarter, our defense business has largely returned to normal operations. Within our Aerospace segment, pandemic-related travel limitations resulted in lower demand for aircraft services due to reduced flight activity, and disrupted the aircraft sales process by limiting our ability to arrange demonstration flights and coordinate in-person access to customers. To de-risk elements of the supply chain and better align production with demand, we have reduced our aircraft production rate until such time that the marketplace supports future increases. Accordingly, we have adjusted staffing levels and taken other cost control measures. The Review of Operating Segments includes additional information on the full-year results for each of our segments. We expect COVID-19 to continue to negatively impact our businesses, particularly Aerospace, until the large economies of the world recover from the effects of the pandemic. As air travel resumes, we expect aircraft services volume to increase, but we could see some future aircraft deliveries delayed to the extent customers have difficulty traveling to take possession of their aircraft. In addition, should the global economy experience a significant extended downturn from the pandemic, demand for our aerospace products and services would likely be impacted. We believe the support by the DoD, and the U.S. government generally, of the defense industrial base has helped and will continue to help mitigate the effects of disruptions on our U.S. defense business. Our non-U.S. defense business will be impacted to varying degrees based on the response of the countries in which they operate. We will continue to assess further potential consequences to our employees, business, supply chain and customers, and take actions to mitigate adverse outcomes. We took actions in 2020 to strengthen our liquidity and financial condition. In March 2020, we issued $4 billion of fixed-rate notes to repay $2.5 billion of fixed- and floating-rate notes that matured in May 2020 and for general corporate purposes, including the repayment of a portion of our borrowings under our commercial paper program. In addition to this long-term borrowing, we renewed our access to $5 billion of credit facilities. While part of our pre-COVID-19 planning, this liquidity preserves our financial flexibility during the pandemic. We believe that our cash flows from operations and borrowing capacity are sufficient to support our short- and long-term liquidity needs. With approximately 70% of our revenue from the U.S. government, government spending levels — particularly defense spending — influence our financial performance. On December 27, 2020, the fiscal year (FY) 2021 defense appropriations bill was signed into law. It totaled $696 billion, a modest increase over FY 2020, and included $627 billion in the base budget in compliance with the previously established spending caps and $69 billion for overseas contingency operations. 30 OUR MARKETS