Neutral States Liechtenstein), Turkey, and Yugoslavia The Finns were attacked by the Soviet Union in the Finnish–Soviet War (1939–1940), and consequently joined in the German attack plan BARBAROSSA in June 1941, waging what Finns called the “Continuation War” against their Russian enemy to the east Denmark, Norway, Belgium, Luxembourg, and the Netherlands were all attacked by Germany in April or May 1940 Italy chose to declare war on the Allies and attacked France on June 10, 1940, after the Wehrmacht had already effectively won the FALL GELB campaign On October 28, 1940, Greece was invaded by Italy Yugoslavia was invaded by Germany and Italy on April 6, 1941 Hungary refused to participate in the invasion of Poland in 1939, but it collaborated in Axis redistribution of territories in the Vienna Awards Its acquisitions committed Budapest to Berlin, as a final German victory became the only outcome that could assure it kept the new territories Hungary joined the Axis alliance on November 20, 1940 It joined in the invasion of the Soviet Union on June 27, 1941 Bulgaria adhered to the Tripartite Pact on March 1, 1941 It permitted German troops to cross its territory to invade Greece and agreed to occupy Macedonia Then it joined the Axis invasion of Yugoslavia However, it stayed out of the German war with the Soviet Union until September 1944 It fought only a two day war against the invading Red Army before switching sides and declaring war on Germany Portugal maintained a highly profitable mineral trade with Germany until it became clear the Axis states would lose, then bent the rules under great pressure from London and Washington to favor the Allies by ending those exports and permitting Allied bases in the Azores Sweden behaved similarly with regard to armaments and iron ore, shipping supplies to Germany until the Germans were no longer able to retaliate Spain was formally neutral throughout the war, but leaned hard toward active participation and membership in the Axis until near the end of 1942, when landings by the Western powers in North Africa permanently dissuaded Madrid from taking up belligerency Turkey refused all entreaties and deflected threats from both sides for most of the war Istanbul declared war on Germany in February 1945, however, under intense pressure from the Western powers The Soviet Union was the most important official European neutral in 1939 In fact, it was really an associated power of the Axis alliance from August 1939 until June 1941, cooperating in the attack on Norway and cheering German defeat of France and expulsion of Great Britain from the continent Joseph Stalin even offered to join the Axis That proposal was ignored by Adolf Hitler, who intended to attack the Soviet Union Outside Europe, Japan and the United States remained formally neutral until December 1941 However, Japan was clearly more than tilted toward the Axis as an adherent to several armed and diplomatic pacts The United States leaned hard toward the Western Allies, including rising active participation in the naval war in the Atlantic in 1941 The Soviet Union and Japan observed strict neutrality toward their respective wars with each others’ allies until August 8, 1945, when the Red Army launched its Manchurian offensive operation Most of Asia and Africa was under colonial rule in 1939, with each colony following the lead of its metropolitan master Burma was invaded by the Japanese Neutral Thailand later 779