WWII: days taken for successful Axis invasions 1939-1941

Throughout the Second World War, the Axis powers successfully used tactics that surprised and overwhelmed their enemies in order to annex or occupy territories, sometimes within a matter of hours. The element of surprise was crucial in these attacks, and many countries were invaded simultaneously to maintain this advantage.

Blitzkrieg

The German military was considered the most effective at this, rapidly pushing into neighboring countries with waves of tanks and armored vehicles before the a defense could be organized. Air and naval power was also used strategically to take important logistical and transport centers, and cause further disruption to supply lines. This became known as Blitzkrieg ("lightning-war"). Through the use of these tactics, Germany was able to defeat France, Europe's largest military power at the time, in just six weeks. Smaller nations such as Denmark and Luxembourg fell within a matter of hours, whereas the defenses of Norway and Estonia were able to hold out for longer by retreating to fortified northern or island positions (although most of their territories were taken quickly). The Italian military was less adept at such tactics - an attempted invasion of Greece was rushed and badly mismanaged, with the Greeks even pushing the invading forces back into Albania for several months, before a joint-Axis force invaded via Yugoslavia and Bulgaria and overran the country in April 1941. Operation Barbarossa, the surprise German invasion of the USSR, was launched just two months later - Blitzkrieg tactics saw the Germans quickly push as far as Moscow before the end of the year, before the Soviets were able to stall out the attack and reorganize.

Pacific Theater

As Europe's Eastern Front turned into a war of attrition in late 1941, the Empire of Japan began its own aggressive expansion. On the morning of December 7^th or 8^th (depending on time zone), the Japanese launched a number of attacks on American, British, and Dutch territories across the Pacific and Southeast Asia. The most famous of these was the attack on Pearl Harbor, which brought the United States into the war, but this was just one of many targets on the day. Thailand was also invaded and capitulated within five hours of invasion when it then joined the Axis powers. Many smaller American and British garrisons held out for some days or weeks, but were outnumbered and eventually overrun. The loss of the Philippines is considered by some to be the biggest U.S. defeat in the Second World War, while the seizure of the Dutch East Indies marked a significant victory for Japan due to its abundant oil resources. It was not until the Japanese made it to the Solomon Islands and New Guinea, where their expansion was eventually contained by joint Commonwealth and U.S. forces.