For more than seven decades, the North Atlantic Treaty Organization (NATO) has served as the cornerstone of Western security, built on the guarantee that an attack on one member is an attack on all.
Donald Trump Threatens To Leave NATO
Yet in recent years—and especially during 2026—that bedrock assumption has faced unprecedented pressure from Washington. President Donald Trump has repeatedly questioned the value of the 32-nation alliance, openly floating the idea of withdrawing the United States or scaling back its military footprint in Europe.
A Longstanding Grievance Over Burden-Sharing
Trump’s skepticism toward NATO is rooted in a belief that the alliance represents a lopsided deal for American taxpayers. Since his first presidential campaign, he has argued that wealthy European nations rely too heavily on the U.S. military umbrella while underfunding their own armed forces.
Although European allies have poured hundreds of billions of dollars into defense upgrades in recent years—prompted largely by Russia’s invasion of Ukraine and sustained American pressure—Trump has continued to demand higher spending benchmarks, pushing for members to commit up to 5% of their gross domestic product to defense. To the White House, anything short of overwhelming European self-reliance amounts to subsidizing foreign security at the expense of domestic priorities.
Flashpoints in 2026: The Iran Conflict and Strategic Friction
Tensions reached a boiling point in the spring of 2026 following the outbreak of conflict involving the United States, Israel, and Iran. When Washington sought direct military assistance from NATO partners to support strikes and help secure maritime traffic through the Strait of Hormuz, several major European allies declined to join offensive operations, pointing out that NATO is strictly a defensive pact limited to the North Atlantic area.
The refusal triggered sharp backlash from the Oval Office. Labeling NATO a “paper tiger,” Trump declared that U.S. membership was “beyond reconsideration” once the Middle East crisis concluded. Compounding the rift were broader geopolitical disagreements, including European pushback against Trump’s renewed push to acquire Greenland and diverging approaches to managing security threats in the Indo-Pacific.
Can a President Unilaterally Exit NATO?
Despite the fiery rhetoric—and even after Trump stated at the July 2026 NATO summit in Ankara that the U.S. would remain in the bloc for the time being—the threat of an eventual exit continues to cast a shadow over transatlantic relations. However, leaving the alliance is far more complicated than issuing an executive order.
In 2023, the U.S. Congress passed bipartisan legislation barring any president from unilaterally withdrawing from NATO without either a two-thirds supermajority vote in the Senate or an explicit act of Congress. Lawmakers further reinforced those guardrails in late 2025 with defense restrictions designed to prevent the Pentagon from drastically slashing troop numbers below 76,000 in Europe or surrendering key military installations without congressional approval. While constitutional scholars debate whether a president could challenge those limits in court, the political reality in Washington remains a major obstacle to a formal exit.
Reshaping European Defense
Even without a formal withdrawal, Trump’s threats have already transformed the alliance. Recognizing that American patience is wearing thin, European leaders are accelerating efforts to build independent military capabilities, expand joint defense manufacturing, and assume primary responsibility for conventional deterrence on the continent. Whether Trump’s rhetoric is intended as a hardball negotiating tactic or a genuine prelude to disengagement, it has forced NATO into a new era—one in which Europe can no longer take American protection for granted.
