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.
World War II by country
Costa Rica joined the Allies on 8 December 1941. The leftist administration of President Rafael Ángel Calderón Guardia was hostile to Nazism and introduced numerous measures to decrease German influence in the country. Costa Rica declared war on Japan the day after the attack on Pearl Harbor, and on Germany and Italy shortly afterwards.