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.
European theatre of World War II
Full-scale war in Europe began at dawn on 1 September 1939, when Germany used her newly formed Blitzkrieg tactics and military strength to invade Poland, to which both the United Kingdom and France had pledged protection and independence guarantees. On 3 September 1939, Britain and France declared war on Germany and British troops were sent to France, however neither French nor British troops gave any significant assistance to the Poles during the entire invasion, and the German–French border, excepting the Saar Offensive, remained mostly calm, this period of the war is commonly known as the Phoney War.