On November 18, 2019, Secretary of State Mike Pompeo stated that the “establishment of Israeli civilian settlements in the West Bank is not per se inconsistent with international law.” This announcement contrasts with the approach taken by the State Department late in the Obama administration. Although embraced by Israel, the position announced by Pompeo was criticized by Palestinians, Security Council members and other states, who maintain that Israeli settlements in the West Bank violate international law. In January of 2020, the Trump administration released its proposed peace plan for the Israelis and Palestinians, which met with approval from Israeli leaders and rejection from Palestinian leaders.

The United States requested environmental consultations with South Korea under the United States-Korea Free Trade Agreement (KORUS) in September 2019. This request occurred on the same day as the release of a report to Congress raising concerns about South Korea's response to illegal, unreported, and unregulated fishing. Following the consultations, South Korea amended its law regulating the Korean fisheries industry in order to make more enforcement mechanisms available.

In late November of 2019, Congress passed the Hong Kong Human Rights and Democracy Act of 2019 (HKHRDA) with overwhelming bipartisan backing. Although its substantive provisions were modest in scope, this bill sent a strong indication of congressional support for protesters in Hong Kong. Despite having some reservations about this bill, President Trump signed it and a companion bill into law on November 27. The following month, Congress signaled attention to another human rights situation in China—the treatment of Uighurs in Xinjiang—by including a provision in the National Defense Authorization Act for Fiscal Year 2020 that requires an executive-branch report on this issue.

On November 15, 2019, President Trump pardoned or otherwise removed punishments for three members of the military—Lieutenant Clint Lorance, Major Mathew Golsteyn, and Chief Petty Officer Edward Gallagher—who had been found to commit, or had allegedly committed, criminal acts abroad that amounted to war crimes. These actions follow Trump's May 2019 pardon of First Lieutenant Michael Behenna, who had been found guilty of murdering a detainee in Iraq. These intrusions into military proceedings were an unusual use of the president's pardon power and have raised concerns about the U.S. commitment to international humanitarian law.

After Russia targeted the 2016 presidential election, U.S. government authorities repeatedly warned about the prospects of foreign interference in and influence on the 2020 election. Throughout the fall of 2020, government officials and private companies took a number of actions to address threats to the election, including issuing public warnings, imposing sanctions, and taking down foreign government-linked accounts. In a declassified report released in March 2021, the intelligence community concluded that although Russia and Iran carried out influence operations to affect the election, there are “no indications that any foreign actor attempted to alter any technical aspect of the voting process in the 2020 US elections, including voter registration, casting ballots, vote tabulation, or reporting results.” In December 2020, however, U.S. cybersecurity firm FireEye disclosed that it suffered a breach by a nation-state sponsored actor, and numerous U.S. government agencies soon revealed that they too had been breached in intrusions widely attributed to Russia.

On January 3, 2020, the U.S. military conducted a drone strike near Baghdad International Airport that killed Qasem Soleimani, the leader within the Iranian military of the Quds Force of the Islamic Revolutionary Guard Corps (IRGC). The Trump administration initially appeared to justify the strike as an effort to deter imminent attacks on U.S. embassies and personnel, but later insisted that Iran's actions in the months leading up to the strike triggered the U.S. right to self-defense. Domestically, the Trump administration claimed the authority to carry out the strike based on both the president's inherent constitutional powers and the Authorization for Use of Military Force Against Iraq passed by Congress in 2002. In the aftermath of the strike, Iraq voted to expel U.S. troops from its territory, and Iran conducted a missile strike on American bases in Iraq. Iran also announced that it would cease to observe limits on its production of nuclear fuel—a core tenet of the Joint Comprehensive Plan of Action (JCPOA), from which the United States withdrew in 2018.

On December 10, 2020, President Donald J. Trump reversed decades of U.S. policy by announcing that the United States would recognize Moroccan sovereignty over Western Sahara as part of a deal in which Morocco would normalize relations with Israel. Despite a 1991 UN truce and continued calls by the UN Security Council for Morocco and the Polisario Front to reach a mutually agreeable solution, neither side has relinquished its claim of sovereignty over Western Sahara. Trump's announcement ended nearly thirty years of U.S. support for UN-led negotiations and places the United States at odds with the majority of the international community, which swiftly criticized the U.S. action as a violation of the right to self-determination.

President Trump first announced his plans for increasing U.S. military capabilities in space in 2018. In August 2019, his administration created the United States Space Command. With the passage in December 2019 of the 2020 National Defense Authorization Act, the United States established the United States Space Force as a new branch of the armed forces. These developments do not directly implicate international law, but they reflect a growing divergence between the U.S. approach to space and that taken by the UN General Assembly.

The newly inaugurated administration of President Joseph R. Biden, Jr. took immediate steps to reengage with a variety of international institutions and agreements from which the Trump administration had withdrawn. On January 20, 2021, the administration deposited with the United Nations a new instrument of acceptance of the Paris Agreement on climate change, and it halted U.S. withdrawal from the World Health Organization (WHO). On January 21, the United States announced that it would participate in the COVID-19 Vaccines Global Access (COVAX) Facility, an international vaccine distribution scheme. The Biden administration also announced that it would reengage with and seek election to the UN Human Rights Council, and it quickly reached agreement with Russia for a five-year extension of the New Strategic Arms Reduction Treaty (New START), the last remaining arms control agreement between the two countries. These early moves are consistent with the foreign policy strategy President Biden previewed during the campaign when he promised to “renew American leadership” and “[e]levate [d]iplomacy.” In his first speech on foreign policy as president, delivered at the U.S. State Department on February 4, Biden asserted that “America is back” and that “[d]iplomacy is back at the center of our foreign policy.” To implement these objectives, Biden has appointed a slate of experienced foreign affairs officials, many of whom worked in the Obama administration.

In the final months of his administration, President Donald Trump issued a variety of pardons and commutations, including a number related to foreign relations. His decision to issue full pardons to four former Blackwater contractors, who were convicted of killing Iraqi civilians in the 2007 Nisour Square incident, drew particular condemnation and continued a pattern of clemency grants related to war crimes committed abroad. Trump also granted clemency to his former national security advisor, Michael Flynn, and other associates who were convicted as a result of Special Counsel Robert S. Mueller III's investigation into Russian interference in the 2016 presidential election. Additionally, Trump pardoned the Israeli handler of Jonathan Pollard, a convicted U.S. spy.