The debate in the United States over a potential withdrawal from NATO has evolved into a power struggle between Congress and the White House, centered on a critical question: Can the president withdraw unilaterally?
In 2023, Congress attempted to put the brakes on this possibility by declaring, โNo withdrawal from NATO with a single signature!โ However, the judiciary has historically avoided issuing clear rulings in similar crises. This ambiguity is testing not only NATOโs future, but also whether the United States is governed by institutional leadership or by the instincts of personal leadership. A U.S. withdrawal would weaken European security, create strategic openings for Russia and China, and raise a fundamental question: will the transition of global leadership occur in a controlled manner, or through crisis?
The U.S. Constitution clearly outlines how international agreements are made: a treaty signed by the president enters into force only with Senate approval. However, when it comes to withdrawing from an agreement, the issue becomes far more complex and contentious.
Presidents have tended to interpret this constitutional silence in their own favor. In fact, in 2020, the Department of Justiceโs Office of Legal Counsel (OLC) argued that the president could withdraw from treaties unilaterally based on executive authority in foreign policy. This interpretation effectively elevates the president to a near โsole authorityโ in matters of international agreements. Congress, however, strongly disagrees.
When it comes to NATO, the issue extends far beyond a technical constitutional debate. NATO is the backbone of the Western order established after World War II.
For this reason, Congress sent a clear message in 2023: no president can withdraw from NATO alone. Under this framework, either a two-thirds Senate approval or explicit congressional legislation is required. This move is less a legal adjustment than a political alarm. In essence, Congress is saying: โThis decision cannot be left to one person.โ
One of the most striking aspects of this debate is the judiciaryโs reluctance to take a definitive stance. A similar issue reached the Supreme Court in the 1978 case Goldwater v. Carter, but the Court avoided ruling on the merits.
At the center of that case was President Jimmy Carterโs historic shift in China policy. On December 15, 1978, the Carter administration announced that the United States would recognize the Peopleโs Republic of China as the sole legitimate government of China starting January 1, 1979. As a result, Washington would cease diplomatic recognition of the Republic of China (Taiwan).
In that context, on December 23, 1978, the State Department notified Taiwan that the 1954 U.S.โROC Mutual Defense Treaty would be terminated in accordance with its own termination clause, effective January 1, 1980. Article 10 of the treaty allowed either party to terminate the agreement with one yearโs notice.
This is where the constitutional crisis began. The Constitution clearly establishes a division of powers in making treaties: the president negotiates, and the Senate approves by a two-thirds vote. But it says nothing about withdrawal. Goldwater and other members of Congress argued precisely this point: โIf a treaty is established with congressional consent, then the president cannot terminate it alone.โ
The case brought this fundamental separation-of-powers question before the Court.
This situation reflects a recurring feature of the American system: some crises are not resolvedโthey are postponed. However, in a matter with global consequences like NATO, the cost of postponement could be far greater.
In theory, this is a constitutional law issue. In practice, it is a power struggle. The president seeks to preserve the ability to act swiftly in foreign policy, while Congress aims to balance that power and maintain its institutional authority.
But the real question is this: in a moment of crisis, who prevails? If a president declares withdrawal from NATO, taking the political risk, can Congress realistically stop it?
There is no clear answer.
Beyond NATO
This debate is not limited to NATO. At its core lies a larger question: will the United States sustain its global leadership through institutional wisdom, or through individual leadership instincts?
During the Cold War, American power stemmed from a combination of economic strength, military superiority, political influence, and institutional stability. Alliances like NATO were concrete expressions of that stability. Today, however, populist rhetoric, domestic polarization, and global competition are making the United States more inward-looking and more fragile.
A U.S. withdrawal from NATO would weaken Europeโs security architecture, open new strategic space for Russia and China, and call into question Americaโs global leadership.
For this reason, the issue is less legal than geopolitical. To understand a potential U.S. withdrawal from NATO, we must look back a century. This moment resembles a historical turning point in the transfer of global leadership. In the early 20th century, the global order was centered on the United Kingdom. However, two world wars, economic exhaustion, and the unsustainable costs of empire gradually forced London to retreat. This was not a โcollapse,โ but a managed transfer of power.
Today, the United States stands at a similar crossroads. The central question is whether this transfer of power will unfold through escalating conflictโbeginning with tensions involving Iran and potentially expanding to confrontation with China and Russiaโor whether it can be managed through a more controlled and gradual transition.
History shows that both outcomes are possible. Britain largely lost its dominance through war but ultimately managed to transfer leadership. The United States, however, remains the architect of the current system and still possesses the capacity to manage this transition.
Yet this is precisely where the dilemma lies: can this transfer of power be managed, or will it occur only after uncontrolled competition spirals into a Third World War?
Ultimately, the debate is not merely about NATO withdrawal. The real question is not how global leadership has ended in the pastโbut how it will end this time.
When Britain stepped back, a stronger and more cohesive actorโthe United Statesโwas ready to take its place. Today, if the U.S. retreats, no single power will fill the vacuum. Instead, a fragmented balance will emerge among China, Russia, and various regional actors.
