Diplomatic Relations Between Spain and the United States in 1966

In 1966, the diplomatic relations between the United States and Spain regarding overflying Spain with aircraft carrying nuclear weapons were a significant point of contention between the two countries. At the time, Spain was under the rule of General Francisco Franco, who had come to power after the Spanish Civil War that ended in 1939.

The United States and Spain had signed a defence agreement in 1953, known as the "Agreement for Cooperation for Defence" or the "Mutual Defence Assistance Agreement." This agreement allowed the United States to establish military bases on Spanish territory, including Rota Naval Base and the Moron Air Base, which were strategically important for American military operations, particularly during the Cold War.

As part of the defence agreement, the United States sought permission to use Spanish airspace for the transit of aircraft, including those carrying nuclear weapons. This became a sensitive issue for Spain, as many Spaniards were opposed to the presence of nuclear weapons on their soil, fearing the risks associated with hosting such weapons in their country. There were also concerns that Spain could become a target in the event of a nuclear conflict.

The overflights of aircraft carrying nuclear weapons generated considerable public opposition and political debates within Spain. Despite this, the Franco regime allowed the United States to continue using Spanish airspace for nuclear-armed aircraft. The decision to permit these overflights was largely due to Spain's reliance on American military and economic aid, which the Franco regime saw as vital for its survival and economic recovery after the devastation of the Spanish Civil War.

In 1970, the situation changed somewhat, partly as a result of the Palomares Incident, when Spain and the United States signed a new defence agreement known as the "Agreement on Defence and Economic Cooperation." This agreement stated that nuclear-armed aircraft could still use Spanish airspace but required that nuclear weapons themselves be stored and managed in a manner that ensured the safety and security of Spanish citizens.

Despite these agreements, public opposition to the presence of nuclear weapons continued, and protests against the US military presence in Spain persisted throughout the later decades of Franco's rule. The issue of nuclear overflights remained a contentious topic in US-Spain relations until the end of the Franco regime and beyond.

These agreements have been strengthened since 1970 by the Agreement of Defence Cooperation Between the U.S.A. and the Kingdom of Spain, signed on the 1st of December 1988 as revised by the Protocol of Amendment of the 10th of April 10 2002, the Second Protocol of Amendment, signed on the 12th of October, 2012, and the Third Protocol of Amendment, signed on the 17th of June 2015. These agreements were further bolstered in 2022 during a meeting between President Pedro Sanchez and President Joe Biden, when both leaders agreed to a new Joint Declaration between Spain and the United States, updating and strengthening the strategic relationship the two countries share.

1. Agreement on Defense Cooperation.
2. United States - Spain Diplomatic Relations.