The implementation of a new 10% global customs tariff by United States (US) President Donald Trump, and the subsequent 6-3 cancellation of previously announced broad tariffs by the US Supreme Court, constitutes a critical turning point not only as a trade policy debate but also in terms of the separation of powers, the limits of presidential authority, and the future of the global economic order. The Court’s ruling that the tariffs implemented by the President—based on the International Emergency Economic Powers Act (IEEPA) of 1977—involved an overreach of authority has limited the executive branch’s capacity for maneuver in the field of trade by subjecting it to judicial review. This decision appears to have reaffirmed the central position of Congress’s taxing power within the American constitutional system.
Chief Justice John Roberts, who authored the majority opinion of the Court, emphasized that when Congress delegates its tariff-setting authority, it does so in an explicit and limited manner. This situation has served as an institutional reminder against the executive branch.[1] Particularly noteworthy is the fact that two conservative justices appointed by Trump—Amy Coney Barrett and Neil Gorsuch—joined the decision to vacate. This picture demonstrates that the ruling was evaluated not merely on ideological grounds, but within the context of constitutional jurisdictional boundaries. Consequently, the matter has been shaped as a constitutional debate regarding the scope of the presidency’s emergency powers, rather than Trump’s trade policy preferences.
On the other hand, Trump’s declaration of a new 10% global tariff despite the ruling has revealed that the executive branch has no intention of backing down. The President’s rhetoric of sustaining tariffs through “alternative laws” has shown that the White House will continue to use trade policy as a strategic tool.[2] This situation has confirmed that trade policy in the US is increasingly becoming an element of domestic political polarization. The President’s harsh criticism of the Republican justices who joined the ruling has indicated that tensions between the judiciary and the executive branch may escalate.
From an economic perspective, the ruling was welcomed positively by the markets in the short term. The rise in the S&P 500 index indicates that the business world evaluates the reduction of legal uncertainty and the potential for refunds as a positive development. For American small and medium-sized enterprises (SMEs) manufacturing in China, this decision has created a “breathing space.” However, Trump’s statement that the refund process could take years suggests that uncertainty has not been completely eliminated. This may cause investment decisions to be shaped cautiously in the medium term.
Regarding the future of the US, the issue is not merely the tariffs themselves; the primary concern is the question of the legal grounds upon which the president can utilize trade policy tools. If the White House continues similar practices by relying on different legislations, a new conflict of authority may arise between Congress and the executive. This could trigger a broader debate concerning the limits of the presidential model in the American political system. Especially during election periods, the use of trade as a populist rhetorical tool may deepen the tension between economic rationality and political mobilization.
On a global scale, this ruling has had a twofold effect. On one hand, it signaled that domestic legal checks and balances are functioning against unilateral trade measures. This has strengthened the perception among allies such as the EU, Canada, and Japan that institutional stability is being preserved. On the other hand, Trump’s announcement of new tariffs has reinforced the conviction that predictability in US trade policy is weakening. This contradictory picture has raised question marks regarding the global economic leadership of the US.
In terms of relations with China, the developments have presented a more complex picture. The Trump administration’s defense of tariffs as “tools that encourage domestic production” has demonstrated that the strategy of economic pressure against China will persist.[3] However, the Supreme Court decision has revealed the legal limits of this strategy. From China’s perspective, the restriction of the executive by US domestic law may have provided short-term relief; however, Trump’s will to sustain tariffs through alternative means suggests that trade wars will not end completely.
US relations with its allies have also been affected by this process. Mexico and Canada, in particular, were among the countries initially targeted. Considering the integration of North American supply chains, tariffs have become an element that strains regional economic cooperation. The court decision was evaluated as a diplomatic gain for these countries. However, the new 10% global tariff has led to allies becoming targets once again. This situation carries the potential to weaken the trust-based relations of the US with its trade partners.
In the long run, the most significant effect has been the redefinition of the institutional ground of trade policy in the US. If Congress enacts new regulations that narrow the executive’s emergency powers, the president’s unilateral trade moves could be limited. Otherwise, the executive branch will be able to continue pursuing similar policies using different legal tools. This process has constituted an example testing the durability of checks and balances in American democracy.
Within this framework, the emerging picture has shown that trade policy in the US is no longer just an economic tool; it has become a strategic field shaped at the intersection of constitutional boundaries, political legitimacy, and claims of global leadership. This tension between the executive and the judiciary has revealed how the American state structure responds in moments of crisis; at the same time, it has reminded international actors that US domestic law can be decisive over foreign policy. However, the President’s unyielding rhetoric has brought to the fore the question of to what extent legal limits can resist political will. Consequently, the issue has transformed into a broader debate regarding the institutional framework within which American power will be utilized, rather than just the cancellation of tariffs.
As a result, the Supreme Court’s decision has shown that constitutional boundaries are being preserved; however, Trump’s new tariff move has revealed that uncertainty in trade policy persists. These developments have been of a nature to produce long-term effects on the global economic leadership of the US, its relations with its allies, and its competition with China. In the upcoming period, the tension between the legal ground of trade policy and political strategy may become one of the fundamental determinants of American domestic and foreign policy.
[1] Sherman, Natalie. “Trump Brings in New 10% Tariff as Supreme Court Rejects His Global Import Taxes”, BBC News, www.bbc.com/news/articles/cn8146l0n55o, (Access Date: 22.02.2026).
[2] ibid.
[3] ibid.
