NATO after the rupture

The clause that could not be used

Article 5 has been invoked once in the alliance's history, after 11 September 2001, on behalf of the United States. It could not be invoked in 2026 because its machinery routes through the North Atlantic Council, in which the aggressor holds a seat and a veto, and because the guarantee was written to describe an attack from outside.

Europe reached instead for Article 42.7 of the Treaty on European Union — a mutual assistance clause it had written for itself, activated for the first time in the circumstances it had never planned for.

What continued

Consultation continued: Article 4 was invoked twice in eleven days. Decision-making continued: thirty-one members adopted a joint declaration on Danish territorial inviolability in American absence. The Nuclear Planning Group convened without the American delegation and put a host-nation perimeter decision on the alliance record.

Eastern flank rotations were never interrupted. Under the basing lockout, allied governments explicitly exempted them: whatever else was happening in the Atlantic, nobody was willing to thin the line facing Russia in order to punish Washington.

The unresolved question

The alliance now contains a member at war with three other members, holding two members' territory under occupation, and storing nuclear weapons on three members' soil behind their police cordons. No provision of the treaty addresses any of these situations. There is no expulsion mechanism and no suspension mechanism; Article 13 provides only for voluntary withdrawal on one year's notice, which the United States has not given.

Legally, the alliance is intact and unanimous on paper. Operationally it has become a thirty-one member European defence organisation with an American observer that does not attend.

See also

• The North Atlantic Council walkout
• Mark Rutte
• The Anglo-French combined command