The outcome of the 1986 Spanish NATO membership referendum committed the Spanish government (then the Second González government) to negotiate the reduction of the United States military presence in Spain. Spain insisted that the F-16 aircraft be removed from Torrejón as a condition for renewal of the base agreement, and the Spanish government threatened to expel all United States forces in Spain if this demand were not accepted. The United States felt that even though Italy subsequently agreed to station the F-16 wing at Aviano Air Base, the cost of transfer would be high, and the unit would be in a more exposed position to Warsaw Pact forces.