A NATO member cannot be expelled. The North Atlantic Treaty, signed in 1949, sets out how countries join and how they may voluntarily leave, but it contains no provision for forced removal. That silence is reinforced by the alliance’s consensus rule: every NATO decision requires the agreement of all 32 members, which would include the country being pushed out.1NATO. NATO Member Countries
Why the Treaty Has No Expulsion Clause
The Washington Treaty has been NATO’s legal foundation since April 4, 1949.2Office of the Historian. North Atlantic Treaty Organization (NATO), 1949 It addresses membership in only a handful of articles, and none of them contemplate removal.
Article 10 covers accession. Any European state may be invited to join if all existing members unanimously agree that the candidate can uphold the treaty’s principles and contribute to North Atlantic security.3NATO. The North Atlantic Treaty There is a matching mechanism for leaving, but not for being made to leave.
Article 2 tells members what they should do once inside: strengthen their free institutions, promote stability, and encourage economic cooperation.3NATO. The North Atlantic Treaty These commitments are aspirational. A member that drifts from democratic norms may draw criticism, but Article 2 carries no enforcement power and no consequence for backsliding.
Article 13 sets out the one exit route: voluntary withdrawal. A member gives notice to the United States, which serves as the treaty’s depositary, and the withdrawal takes effect one year later. Throughout that year the departing country remains a full member, including under the Article 5 collective defense obligation.3NATO. The North Atlantic Treaty The article originally required a twenty-year waiting period before it could be invoked, but that threshold passed decades ago.4Congress.gov. Separation of Powers and NATO Withdrawal Even so, no member has ever formally invoked it.
The consensus rule closes the door the treaty already left shut. Every NATO decision, at every level from the North Atlantic Council down, requires unanimous agreement. There is no voting and no override.5NATO. Consensus Decision-Making at NATO So even if some future clause created an expulsion procedure, it would presumably require the same consensus, meaning the targeted country would have to vote for its own removal. You cannot be forced out of a club that does not vote.
What NATO Can Actually Do About a Problem Member
Without a formal removal or suspension mechanism, the alliance has to work with softer tools: joint statements, private diplomatic pressure, and informal exclusion from specific meetings, planning sessions, or programs. None of these touch a country’s formal membership status.
Turkey’s purchase of Russia’s S-400 missile defense system is the clearest recent example. Allied governments argued the system was incompatible with NATO’s integrated air defenses and posed a risk to the F-35 stealth fighter program. The United States responded bilaterally by removing Turkey from the F-35 program entirely, cutting off both aircraft deliveries and industrial participation. That was a real penalty, but it happened outside the alliance’s formal structures. Turkey’s seat at the NATO table was untouched.
Hungary has pressed the alliance in a different way, using the consensus requirement to block or slow NATO decisions on support for Ukraine. Because a single member can hold up any collective action, the response has been diplomatic workarounds. Assistance packages get structured so that individual countries can opt out of funding or personnel while the broader effort proceeds.
Defense spending is another familiar friction point. In 2014, NATO leaders pledged to spend at least 2% of GDP on defense, and by 2025 all allies were expected to meet or exceed that guideline.6NATO. Defence Expenditures and NATO’s 5% Commitment Falling short has never triggered any formal consequence within the alliance, though it has generated persistent political tension.
Does International Law Provide Any Path?
Outside the treaty itself, the Vienna Convention on the Law of Treaties offers a theoretical mechanism. Article 60 lets parties to a multilateral treaty respond to a material breach by another party. By unanimous agreement, the remaining parties can suspend the treaty’s operation with respect to the defaulting state or terminate it entirely in their relations with that state. A material breach means either repudiating the treaty or violating a provision essential to its object or purpose.7United Nations Treaty Collection. Vienna Convention on the Law of Treaties
In practice this route is nearly closed. The material-breach threshold is high, and NATO’s core obligations are written in broad, aspirational language that gives members wide latitude. Underspending on defense, blocking a consensus decision, or even buying weapons from an adversary would be difficult to characterize as a violation of a provision essential to the treaty’s purpose. The remaining allies would also have to reach unanimity among themselves, so any single sympathetic member could block the move. And no state has ever attempted to invoke Article 60 against a NATO member, so there is no precedent to follow.
The Theoretical Workaround: Start Over Without the Country
Legal scholars have discussed one drastic alternative. Every other member could invoke Article 13, withdraw from the existing treaty, and immediately negotiate a new alliance that excludes the unwanted country. Functionally that would look like expulsion, though technically it would be a coordinated mass departure followed by a new agreement.
The scenario is not realistic. It would require dozens of nations to synchronize withdrawal notices, endure a one-year gap in which Article 5 obligations would be in flux, negotiate an entirely new treaty, and absorb the diplomatic damage of an openly hostile act against a sovereign ally. That legal experts even raise the option is itself a marker of how thoroughly the treaty forecloses simpler paths.
Partial Withdrawal Is Not Expulsion
One point of confusion is worth clearing up. Two members have pulled their forces out of NATO’s integrated military command while staying in the political alliance, and neither case involved being removed by anyone else. In March 1966, President Charles de Gaulle told the United States that France would leave the integrated military structure to regain full sovereignty over its territory, while remaining a party to the Washington Treaty.8France NATO. Letter from President Charles de Gaulle to President Lyndon Johnson on France’s Withdrawal from the NATO Command Structure France returned to the integrated command in 2009. Greece pulled its forces from the military structure in August 1974, following Turkey’s invasion of Cyprus, and reintegrated them in October 1980. American officials at the time noted that Greece’s steps “could be reversed merely by an announcement to that effect.”9Office of the Historian. Foreign Relations of the United States, 1969-1976, Volume XXX, Greece; Cyprus; Turkey, 1973-1976 Document 26
Both were voluntary and reversible choices by the countries themselves. Neither is an example of NATO removing anyone, because NATO has no way to do that.