Overview
- Spain’s 12 March 1986 consultative referendum endorsed remaining in NATO with 52.5% of the vote on 59.4% turnout.
- The ballot avoided the term ‘OTAN,’ referred to the ‘Atlantic Alliance,’ and tied a ‘yes’ to three conditions: no entry into the integrated military structure, no nuclear weapons on Spanish soil, and a progressive reduction of U.S. forces.
- Spain later revoked the non‑integration pledge in 1999 and is now fully embedded in NATO’s military structure.
- In March 2026 the government declined U.S. requests to use the Morón and Rota bases for an attack on Iran, prompting Trump to rebuke Spain publicly and leaving the diplomatic fallout uncertain.
- Recent polling by the Real Instituto Elcano (July 2025) shows strong majority support for remaining in NATO, even as debate continues over defense‑spending targets.