Starting in February 2016, the United States and Russia reached a series of agreements aimed at establishing a cessation of hostilities in the Syrian civil war and facilitating a political settlement of the underlying conflict. Although the agreements showed initial promise, various breakdowns led the United States to suspend bilateral communications with Russia regarding maintenance of the agreements by October 2016.

On January 27, 2017, President Trump issued an executive order that: (1) prohibited nationals from seven majority-Muslim countries from entering the United States for ninety days; and (2) prohibited individuals from entering into the United States as refugees for 120 days. Courts stayed the order on constitutional and statutory grounds. In response to these stays, President Trump replaced the initial order with a new order that eliminated preferential treatment for refugees fleeing from religious persecution and narrowed the scope of persons prohibited from entering into the United States. Courts again issued stays, holding that the new order violated the Establishment Clause and the Immigration and Nationality Act. The Trump administration appealed, and the Supreme Court agreed to hear the case in October. Along with its grant of certiorari, the Court kept the lower court stays in place except as to people with no connection to the United States either personally or through family.

On July 11, 2017, U.S. Secretary of State Rex Tillerson signed a memorandum of understanding (MOU) between the United States and Qatar, thereby establishing a joint plan to investigate and eliminate the financing of terrorism. The agreement was signed against a backdrop of conflict between Qatar and a number of its regional neighbors, particularly Saudi Arabia. While it appears that negotiations between Qatar and the United States predated the formal standoff between Qatar and its neighbors, Qatar has invoked the MOU to defend itself against Saudi accusations of terror financing.

The law in France regarding waivers of foreign state (or sovereign) immunity from execution of judicial judgments (based largely on consideration of international law principles) has recently undergone significant developments. Previously, French case law had required a foreign state's waiver of immunity from execution to be both express and specific to consider valid the attachment of foreign state property allocated to public services (including bank accounts used for the functioning of both diplomatic missions and delegations to international organizations). In 2015, the French Court of Cassation relaxed the criteria it had previously required for giving effect to waivers of sovereign immunity in such situations, thus facilitating the ability of judgment creditors to attach foreign state property in France. Its decision in the Commisimpex v. Republic of Congo case appeared to put an end to that requirement by abandoning the criterion of a “specific” waiver on the ground that “customary international law does not require a waiver of immunity from execution other than express.” In December 2016, however, the French government enacted new legislation reinstating the need for a specific waiver of immunity for the attachment of the property as well as bank accounts of foreign embassies and diplomatic missions and additionally requiring a court order authorizing the attachment or seizure. As a result, France has now embraced a distinctly more protective approach to the immunity of foreign state assets from attachment and execution of judicial judgments.

Iran, the five permanent members of the UN Security Council, Germany, and the European Union agreed to the Joint Comprehensive Plan of Action (JCPOA) in July 2015. Under the JCPOA, Iran agreed to limit the scope and content of its nuclear program in exchange for relief from various nuclear-related sanctions imposed by the other signatories. Throughout his campaign, President Donald Trump denounced the JCPOA. He said that, if elected, he would “renegotiate with Iran—right after … enabl[ing] the immediate release of our American prisoners and ask[ing] Congress to impose new sanctions that stop Iran from having the ability to sponsor terrorism around the world.” So far, however, the Trump administration has kept the agreement in place. The United States has continued to acknowledge Iran's compliance with the terms of the JCPOA and has waived various sanctions against Iran in compliance with its own obligations thereunder. Iran, by contrast, has charged the United States with failing to live up to its own JCPOA commitments.

In October 2016, Russian President Vladimir Putin suspended the Plutonium Management and Disposition Agreement (PMDA), a bilateral treaty between Russia and the United States governing the disposal of surplus weapons-grade plutonium. A Russian Foreign Ministry director explained that the decision was prompted by a “dramatic change in the situation . . . brought about by the unfriendly steps taken by the United States.” He also cited “the United States’ obvious inability and unwillingness to honour its obligations . . . on time and in full.” The United States expressed disappointment at the suspension, arguing that continued implementation was in both states’ interests.

On April 19, 2016, in The Case Concerning the Resolution of the Question of the Possibility to Execute in Accordance with the Constitution of the Russian Federation the Judgment of the European Court of Human Rights of 4 July 2013 in the Case of Anchugov and Gladkov v. Russia in Connection with the Request of the Ministry of Justice of the Russian Federation (Anchugov & Gladkov (Russ.)), the Constitutional Court of the Russian Federation (Constitutional Court) held that decisions of the European Court of Human Rights (ECtHR) are binding on Russian courts, in accordance with Article 15(4) of the 1993 Constitution of the Russian Federation. At the same time, the Constitutional Court stressed the necessity of ensuring a reasonable balance between the obligation to implement ECtHR judgments and respect for the fundamental principles of the Russian Federation's constitutional system. The Constitutional Court found that because the ECtHR judgment in question implicitly conflicted with provisions of the Russian Constitution, Russian courts are not obliged to comply with the judgment regarding issues that remain in conflict; however, other means are available to the Russian legislature to give effect to the judgment. While the decision marks an important development in Russia's relationship with the European system of human rights, it is not inconsistent with the approach taken by a substantial number of European domestic courts in holding that treaty obligations to enforce decisions of international courts cannot justify violating domestic constitutional norms.

In June 2017, President Donald Trump announced a plan to roll back various steps taken by his predecessor toward normalizing relations between the United States and Cuba. A senior official for the administration announced the plan in a White House press briefing:

In January 2015, a CIA drone killed an Italian aid worker named Giovanni Lo Porto during a strike on an Al Qaeda compound in the Pakistan-Afghanistan border region. In July 2016, the Obama Administration reached a settlement agreement with Lo Porto's family that included a payment by the United States of more than one million euros.

On September 3, 2016, the United States deposited with the UN its instrument of acceptance for the Paris Agreement on Climate Change. The agreement entered into force on November 4, 2016. Following the change of U.S. presidential administrations, new President Donald Trump announced less than seven months later that the United States would withdraw from the Agreement. On August 4, 2017, the United States communicated this intention to the United Nations secretary-general, who serves as the depositary for the agreement.

On April 6, 2017, the United States launched air strikes against a Syrian government airfield, marking a new development in Syria's long-running civil war. U.S. involvement in the conflict had previously been limited to the provision of indirect support for some rebels and the use of direct force against certain nonstate actors, particularly Islamic State of Iraq and the Levant (ISIL). This changed in the wake of April 4, however, when a rebel-held town was hit by a nerve gas attack that killed more than eighty people—including at least thirty children—and injured hundreds more. The attack used Sarin or a Sarin-like substance, which causes death by asphyxiation, often accompanied by blue facial skin and foaming at the mouth. The United States concluded, along with many other states and the NGO Human Rights Watch, that the attack was perpetrated by Syria's Assad regime.

In a case of first impression, the Constitutional Court of Hungary (CCH or Court) ruled on November 30, 2016 that, in exceptional cases, it is competent to consider whether Hungary's obligations to the European Union (EU) violate fundamental individual rights (including human dignity) or Hungarian sovereignty as protected by the Hungarian Constitution. The decision places Hungary squarely within the growing group of EU member states whose constitutional courts have decided that, despite the decisions of the European Court of Justice regarding the primacy of EU law, EU member states are not compelled to violate their domestic constitutional obligations in carrying out their shared EU commitments.

The United States' total trade deficit in 2016 was $502.3 billion. President Trump believes that the deficit—and especially its consequences (“wealth … stripped from our country”), causes (“bad trade deals”), and images (“shuttered factories”)—played a prominent role in his electoral success in 2016. Since taking office, Trump has signed a series of executive orders and memoranda on trade in order to fulfill various campaign promises on this front. The executive orders and memoranda focus mainly on gathering information and laying groundwork for future executive action. Taken together, they signal the Trump administration's intention to address the United States' trade deficits, especially with China.

The United States deposited its instrument of ratification for the Hague Convention on the International Recovery of Child Support and Other Forms of Family Maintenance (the Convention) in September 2016. The Convention entered into force for the United States several months later. Ratification was facilitated by the passage of novel federal implementing legislation that—rather than directly mandating alterations to the domestic legal structure—created a financial incentive for states to change their child support laws. While the Idaho legislature displayed some initial resistance, by early 2016 all fifty states had changed the relevant laws, enabling the submission of U.S. ratification.

The Intermediate-Range Nuclear Forces Treaty (INF Treaty), signed by Ronald Reagan and Mikhail Gorbachev in 1987, obligates the parties “not to possess, produce, or flight-test a ground-launched cruise missile (GLCM) with a range capability of 500 km to 5,500 km, or to possess or produce launchers of such missiles.” In 2014, the State Department reported that Russia was in violation of its obligation not to possess intermediate- or short-range missiles. Russia denied the violation and expressed its own doubts about the United States' compliance with the INF Treaty; the meetings and discussions that followed did not resolve either state's concerns. Subsequent State Department reports in 2015 and 2016 continued to express concern about Russia's violation.

On December 23, 2016, the United States abstained from voting on a United Nations Security Council resolution that condemned Israeli settlement construction, thereby allowing the resolution to be adopted by a vote of 14–0. Israel's response was swift and disapproving.

As the civil war in Syria continues, some of the key actors have sought ways to reduce the conflict's toll on civilians. In May, 2007, Russia and the United States began exploring the possibility of establishing “safe” or “de-escalation” zones. On July 7, this dialogue yielded a trilateral agreement and memorandum signed by Russia, the United States, and Jordan to establish a ceasefire in southwest Syria. The resulting ceasefire—the first in Syria signed by the Trump administration—governs hostilities between Syrian government forces and associated troops on one side and rebels on the other. It began on July 9.

On October 7, 2016, following months of tense interactions between the United States and Russia regarding hacks of high-profile U.S. political organizations, the Department of Homeland Security and Office of the Director of National Intelligence (DNI) issued a joint statement formally accusing Russia of using cyberattacks to influence the U.S. election process. Reports suggest that Russia intended to use the hacks and subsequent information dump to help then-candidate Donald Trump win the presidential election. In response to the cyberattacks, the United States took steps against several Russian individuals and entities. The Obama administration also initiated an extensive review of Russian involvement in the election, which eventually reaffirmed key intelligence conclusions regarding the scope of Russian interference. Several congressional committees have also initiated investigations, all of which are still ongoing as of the date of publication.