World War II or the Second World War was a global military conflict, the joining of what had initially been two separate conflicts. The first began in Asia in 1937 as the Second Sino-Japanese War; the other began in Europe in 1939 with the German invasion of Poland.
This global conflict split the majority of the world's nations into opposing military alliances: the Allies and the Axis powers. It involved the mobilization of over 100 million military personnel, making it the most widespread war in history, and placed the participants in a state of "total war", erasing the distinction between civil and military resources. This resulted in the complete activation of a nation's economic, industrial, and scientific capabilities for the purposes of the war effort. Over 70 million people, the majority of them civilians, were killed, making it the deadliest conflict in human history.
The Allies were victorious, and, as a result, the Soviet Union and the United States emerged as the world's leading superpowers. This set the stage for the Cold War, which lasted for the next 45 years. The United Nations was formed in the hope of preventing another such conflict. The self determination spawned by the war accelerated decolonization movements in Asia and Africa, while Europe itself began moving toward integration.
Carlson's patrol, also known as
The Long Patrol or
Carlson's long patrol, was an operation by the
2nd Marine Raider Battalion under the command of
Evans Carlson during the
Guadalcanal Campaign against the
Imperial Japanese Army from
November 6 to
December 4,
1942. In the operation, the 2nd Raiders attacked forces under the command of
Toshinari Shōji, which were
escaping from an attempted encirclement in the Koli Point area on
Guadalcanal and attempting to rejoin other Japanese army units on the opposite side of the U.S. Lunga perimeter.In a series of small unit engagements over 29 days, the 2nd Raiders killed almost 500 Japanese soldiers while suffering only 16 killed. The raiders also captured a Japanese artillery cannon that was delivering harassing gunfire on
Henderson Field, the
Allied airfield at Lunga Point on Guadalcanal.On
August 7,
1942, Allied forces (primarily
US Marines) landed on Guadalcanal,
Tulagi, and
Florida Islands in the
Solomon Islands. Their mission was to deny the Japanese use of the islands as
bases for threatening the
supply routes between the U.S. and
Australia, and to secure the islands as starting points for a
campaign to isolate the major Japanese base at
Rabaul while also supporting the Allied
New Guinea campaign. The landings initiated the six-month-long
Guadalcanal Campaign.
The
Enigma machine was a
cipher machine used to
encrypt and decrypt secret messages. More precisely, Enigma was a family of related electro-mechanical
rotor machines, comprising a variety of different models.The Enigma was used commercially from the early 1920s on, and was also adopted by the military and governmental services of a number of nations—most famously by
Nazi Germany before and during
World War II.The German military model, the
Wehrmacht Enigma, is the version most commonly discussed.The machine has gained notoriety because
Allied cryptologists were able to
decrypt a large number of messages that had been enciphered on the machine. Decryption was made possible in 1932 by
Polish cryptographers
Marian Rejewski,
Jerzy Różycki and
Henryk Zygalski from
Cipher Bureau. In mid-1939 reconstruction and decryption methods were delivered from
Poland to
Britain and
France. The
intelligence gained through this source, codenamed
ULTRA, was a significant aid to the Allied war effort.
The second
Battle of Smolensk (
7 August 1943 –
2 October 1943) was a Soviet strategic offensive operation conducted by the
Red Army as part of the Summer-Autumn Campaign of 1943 in the Western USSR. Staged almost simultaneously with the
Battle of the Dnieper (
13 August –
22 September), the offensive lasted two months and was led by Generals
Andrei Yeremenko commanding the
Kalinin Front and
Vasily Sokolovsky commanding the
Western Front. Its goal was to clear the
Nazi Germany presence from the
Smolensk and
Bryansk regions. Smolensk had been under German occupation since the first
Battle of Smolensk in 1941.Despite an impressive German defense, the Red Army was able to stage several breakthroughs, liberating several major cities including Smolensk and
Roslavl. As a result of this operation the Red Army was able to start planning for the liberation of
Belorussia. However, the overall advance was quite modest and slow in the face of heavy German resistance, and the operation was therefore accomplished in three stages: August 7–20, August 21–September 6, and September 7–October 2.