Portugal during World War II
Upon the start of World War II in 1939, the Portuguese Government announced on 1 September that the 600-year-old Anglo-Portuguese Alliance remained intact, but that since the British did not seek Portuguese assistance, Portugal was free to remain neutral in the war and would do so. In an aide-mémoire of 5 September 1939, the British Government confirmed the understanding. As Hitler's occupation swept across Europe, neutral Portugal became one of the Continent's last escape routes. Portugal managed to remain neutral throughout the war despite extraordinary pressures from both sides, notably over the strategically located Azores islands and over the wolfram (tungsten) trade.
Military history of Portugal
Salazar gave material and diplomatic aid to Francisco Franco's nationalist forces while maintaining a formal neutrality. A special volunteer force of 18,000, called "Os Viriatos" (in honour of Lusitanian leader and Portuguese national hero Viriatus), led by regular army officers, was recruited to fight as part of Franco's army, even if unofficially. When the civil war ended in 1939, Portugal and Spain negotiated the Treaty of Friendship and Nonaggression (Iberian Pact). The pact committed the two countries to defend the Iberian Peninsula against any power that attacked either country and helped to ensure Iberian neutrality during World War II.