Last December, U.S. President Joe Biden sought to end a controversial immigration program put in place by his predecessor, Donald Trump. That scheme, known as Title 42, relied on an old public health statute to expel more than 2.4 million migrants, including thousands of unaccompanied minors, at the southern border. But before Biden could end Title 42, a coalition of Republican-led states petitioned the U.S. Supreme Court to step in and block the federal government from winding down the expulsions. Without any hearing, and despite grave doubts about whether these states even had the legal right to lodge such a challenge, the Court summarily agreed: it forced Biden to continue the Trump-era program, which remains in place to this day.

The Court’s ruling reflected a growing judicial habit of embracing aggressive legal interpretations to issue decisions that could significantly limit what the United States can and cannot do in the world. Led by the U.S. Supreme Court , domestic courts are poised to reshape the implementation of a vast array of laws and regulations critical to U.S. foreign policy, affecting migration, the treatment of people detained on terrorism-related grounds, and the authority of government agencies crucial to diplomatic initiatives related to health, environmental, and technology policy. This legal activism comes at a time when Congress has largely withdrawn from foreign policy and when the country’s polarization has made it difficult for federal lawmakers to approve new international agreements, especially Senate-ratified treaties, or major statutory changes. As a result, the Biden administration’s foreign policy priorities depend ever more on whether executive branch initiatives invite the scrutiny of an emboldened and antagonistic judiciary.

These developments are at odds with the traditional view of the Supreme Court, which plays up its role as an adjudicator of specific disputes, not as a major driver of foreign affairs. Responsibility for that domain is thought to lie with the White House, the State Department, the Pentagon, and the Department of Homeland Security—entities to which the Supreme Court has historically deferred. But in a few short years, the Court under Chief Justice John Roberts has carved out a new, muscular role in foreign policy that goes well beyond immigration. In the last year alone, it has taken cases that affect transnational security cooperation, the regulation of financial risk, the legal responsibilities of social media companies that operate across borders, and U.S. leadership on climate change. It has done so in ways that buck precedent and stretch the power of the Court beyond its familiar bounds. In effect, the Supreme Court is not just the highest court in the land—it is well on its way to becoming a shadow ministry of foreign affairs.


The Supreme Court has always had a role to play in disputes about federal power. But since the appointment of three new justices under Trump , the Court’s actions have often  appeared to have an especially sharp partisan tilt. Many of the cases that have reached the court in recent years began as litigation filed by Republican state attorneys general or by organizations closely affiliated to Republican coalitions. When an opinion eventually comes out, the justices defer to experts in the executive branch only when it suits them and only erratically recognize judicial precedent. Their interventions cast a wide net. Opinions issued by the Roberts Court routinely take up legal and policy questions that are not raised in the litigation. Such judgments do not change policy directly, but they shift who has power. This shadow ministry in effect decides not just what policy should be but also how policy should be made.

Consider the Court’s June 2022 decision eliminating the Environmental Protection Agency’s power to regulate carbon emissions through the Clean Power Plan, a 2015 rule that limited emissions from power plants. Although federal legislation plainly gave the EPA requisite legal authority to implement the plan, the Court said that the agency did not have the power to decide a “major question,” such as how the government might address climate change .

The decision highlighted a growing challenge in foreign affairs: the increasing entanglement between domestic and international regulatory problems. Americans may have among the highest per capita carbon emissions in the world, for example, but effective climate action requires policy changes in many other countries as well, given that the United States contributes only a fraction of global emissions. What is more, slashing domestic emissions enhances a country’s influence on global climate policy by demonstrating its commitment to serious action, imbuing it with a measure of moral authority and encouraging financial and technological changes with spillover effects for the rest of the world. The Court not only delivered a blow to Biden’s domestic environmental agenda but also undermined the administration’s ability to lead globally.

The Court’s June 2022 ruling in effect prohibited the government from using all its available tools to set climate-change policy without further action in Congress. If this check on the administration’s power simply inserted friction (not outright obstruction) into the process, it might induce helpful deliberation. But a divided Congress will not deliver such support any time soon. Instead, the ruling imposes serious limits on U.S. action at home and abroad. The United States’ global partners and antagonists, no less than domestic observers, see how the Court has rendered the country incapable of effective leadership. The combination of a paralyzed Congress and a muscular Court threaten to trap the United States in a dangerous geopolitical inertia.

The Supreme Court is on its way to becoming a shadow ministry of foreign affairs.

The EPA case is not the only one with international dimensions that the Court has faced. When the Court heard oral arguments in February on whether the social media giants Facebook and Twitter enjoy immunity from federal civil suits, it pondered a decision with wide-ranging repercussions for the transnational public sphere. Similarly, the Roberts Court has heard several challenges to the constitutionality of agencies responsible for financial regulation, such as the Consumer Finance Protection Bureau and the Securities and Exchange Commission. Although rulings in these cases have so far been limited, litigation in the pipeline could derail major regulatory agencies in ways that could send shock waves through the U.S. (and hence the global) financial system.

Supreme Court decisions regarding the authority of federal agencies over export controls, international domestic investment, and antitrust regulations all have global consequences. A relatively flexible, open-ended interpretation of the Sherman Act, the country’s core antitrust statute, for example, can afford the executive branch a great deal of leeway in using antitrust law to rein in the activities of U.S. technology companies abroad. In past decades, the Supreme Court has been reluctant to curtail the power of the president to impose economic sanctions or restrict exports, but the current judiciary is wedded to a narrow, even baroque, conception of the limited scope of executive power. It could chip away at or even destroy the long-standing mechanisms available to the federal government in conducting economic statecraft in an interdependent world.

Courts in previous eras have struggled to reconcile urgent foreign policy with domestic law. After World War II , the Vinson Court set limits on how presidents could seize control of industry on national security grounds when it grappled with President Harry Truman’s mobilization for the Korean War. More often, courts reviewing presidential foreign affairs actions in areas ranging from economic sanctions to immigration were generally deferential to the executive. But the current age of international interdependence—with countries bound together by financial markets, digital technology, concerns about climate change, and migration—makes the international implications of judicial action more inescapable and more consequential. The court’s customary caution when it came to reining in a president’s foreign policy is now clashing with an emboldened majority that seems bent on limiting the power of the federal government. An aggressive Supreme Court willing to closely police domestic policy will also become a bench with an outsize global footprint.

The climate change and Title 42 decisions, for instance, show a Court eager to flex its muscles. In its EPA decision, the Court abrogated to itself a dramatic and unclear new authority. Roberts’s opinion in the decision offers only vague guidance on what constitutes a “major question.” As a result, the opinion licenses the justices to invalidate policies in the future that they disagree with. Even in its infancy, this new theory of “major questions” has already been used to critique proposed rules from the Securities and Exchange Commission and Federal Trade Commission on climate change, privacy, and cybersecurity. All have major foreign policy dimensions.


The EPA decision showcases the Court’s swelling confidence in another way: to strike down the Clean Power Plan, the Court had to ignore much of its own precedent. Until 2022, the idea of a “major questions” exception to an agency’s statutory authority was reserved for once-in-a-generation cases. In 2022, the Court expanded the exception to apply whenever a regulation triggered political contention. This disregard for precedent matters immensely. Unlike any other governmental body, the Court is thought to have the last word on what the Constitution means. If it abandons the traditional habits of judicious caution and respect for precedent, it will have cast off all guardrails.

Fair-minded observers generally agree that the Roberts Court’s low regard for precedent is itself precedent-setting. So, too, is its marked willingness to wade, early and eagerly, into contested policy waters. It does so often without waiting for an issue to develop fully or for the ordinary process of litigation to unfold. The Title 42 litigation reflects an increasingly common Court practice of using emergency powers to change the status quo before a case is even heard.

Why has the Roberts Court changed so much and so quickly? The new, aggressive judicial posture embodies the success of conservative activists, such as Leonard Leo of the Federalist Society. These activists have been lobbying Republican presidents since the 1980s to appoint judges who would cater to their ideological fellow travelers rather than to the American public as a whole. Under Trump, they prevailed. A recent empirical study by Stephen Jessee and two co-authors in the Proceedings of the National Academy of Sciences found that Trump’s appointments to the high court moved that body’s median views far from the preferences of the average American but close to those of the average Republican voter. The predictable result is a Republican-appointed bench that is openly and unabashedly hostile to the policy agenda of Democratic administrations.

This is no secret. Soon after the EPA decision, four conservative justices—Samuel Alito, Neil Gorsuch, Brett Kavanaugh, and Amy Coney Barrett—appeared at the annual dinner of the Federalist Society. They openly affiliated themselves with a plainly partisan ideological project that has connections to many of the litigants in their cases, including Republican attorneys general.


In foreign policy, a Court willing to act in this way is all the more influential when other branches are incapable of action. Congress has become sclerotic when it comes to international matters. For instance, it has failed to renew the Generalized System of Preferences program and the Miscellaneous Tariff Bill, both of which were relatively uncontroversial yet important trade-enabling measures that expired in 2020. The Court also uses tools such as the “major questions” doctrine to weaken the White House on policy initiatives the justices dislike. Thanks to its own interventions, the Court is often the only actor left standing.

Indeed, there are certain ways in which the Court, compared with Congress, has an oddly easier time influencing policy. The justices, after all, set their own agenda by picking from the broad menu of cases that litigants send their way. The Court, moreover, is not Balkanized into functional silos as Congress and traditional bureaucracies are. Justices hear and vote on cases bearing on foreign policy whether they involve terrorism, immigration, antitrust policy, climate policy, or anything else. And federal judges, unlike presidents, don’t have to worry about winning reelection.

The Court’s new, aggressive posture embodies the success of conservative activists.

None of this is to suggest that the Supreme Court should mechanically defer to presidential foreign affairs prerogatives or lose sight of its responsibility to resolve major legal disputes impartially. But many judges and lawyers from various corners of the jurisprudential spectrum have long supported a tradition of restrained judicial action when it impinges upon the country’s foreign policy. This tradition takes on even greater importance at a time when the Court has shown a penchant for acting boldly and bucking precedent.

Policymakers must become savvier at anticipating the possibility that Court decisions about the authority of government agencies could upend major cross-border initiatives such as elements of the Indo-Pacific Economic Framework for Prosperity, the Biden administration’s plan for economic engagement with numerous Asian countries, or the United States-Europe Trade and Technology Dialogue, a program undertaken with the EU to better align policies on trade and technology. Getting state and city governments to buttress such efforts, for example, could help ensure that some degree of international cooperation and harmonization remains possible even if the interventionist Court blocks federal involvement in an initiative.

The present conjunction of great-power competition and an accelerating climate emergency is a dangerous one. U.S. diplomats will face these challenges while also contending with a more aggressive Supreme Court all too willing to buck precedent in the name of orthodoxy and leave less room for prudence in foreign affairs. U.S. policymakers already have enough on their plates. A reckless Court’s shadow foreign ministry only makes a challenging world harder for the United States to navigate.

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  • AZIZ HUQ is Frank and Bernice J. Greenberg Professor of Law at the University of Chicago.

  • MARIANO-FLORENTINO CUÉLLAR is President of the Carnegie Endowment for International Peace and a former justice of the California Supreme Court.
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