Campaigns of World War II

The campaigns of World War II were the military operations that were employed during World War II. Campaigns generally refer to broader strategic operations conducted over a large bit of territory and over a long period of time. Battles generally refer to short periods of intense combat localized to a specific area and over a specific period of time. However, use of the terms in naming such events is not consistent. For example, the Battle of the Atlantic was more or less an entire theater of war, and the so-called battle lasted for the duration of the entire war. Another misnomer is the Battle of Britain, which by all rights should be considered a campaign, not a mere battle.

European Theatre
The European Theatre of World War II encompassed a large number of campaigns and many of the war's largest battles. In particular, the Eastern Front was the site of almost constant campaigning and regular battles.

Polish September Campaign
The Invasion of Poland was fought in Poland between invading German and Soviet forces and defending Polish forces, beginning with the invasion of Poland by Germany under operational plan Fall Weiss on September 1, 1939, and concluding with the surrender of the last Polish military forces on October 6, 1939. Many Polish personnel and forces escaped capture, but the entirety of Poland was captured and the campaign was a success for the invading forces. While France and the United Kingdom declared war on Germany over the invasion, they were unable to render significant aid to Poland during the campaign.

The Phoney War
The Phoney War refers to the conduct of the war in Western Europe, primarily along the Franco-German border, between the declaration of war on September 3, 1939, to the invasion of France and the Low Countries by Germany on May 10, 1940. This period is marked by a distinct lack of active combat operations despite the war status. German forces were fighting in Poland and lacked sufficient strength to mount an offensive, while for a number of reasons, the Allies did not exploit this weakness to go on the offensive themselves on this front.

Winter War
The Winter War fought between Finland and the Soviet Union, was a concurrent war to World War II, and thus is covered in its own main article.

Norwegian campaign
The Norwegian campaign was the battle for control of Norway and its strategic position and influence in regard to mineral resources and access to the Baltic Sea. Both Germany and the Allies planned actions of military intervention, but Germany was first to act, launching their Operation Weserübung on April 9, 1940, ahead of the less well organized Allied campaign in Norway. Part of the campaign was the capture of Denmark by German forces, with Copenhagen falling to Germany within hours. The Norwegian portion of the campaign lasted until June 10, 1940, when the Allied forces completed their withdrawal, allowing Axis occupation of Norway which would last for the remainder of the war.

France and the Low Countries
The Battle of France was launched by Germany with the Fall Gelb operation, when German forces invaded France, Luxembourg, Belgium, and the Netherlands on May 10, 1940. A strong British contingent, the British Expeditionary Force, assisted the French and Belgian forces. The Germans were successful in cutting off large portions of the Allied forces in the Low Countries, forcing evacuation by sea, and in driving rapidly through northern France, precipitating the collapse of the French government. On June 22, the French government signed the armistice with Germany to bring an end to the campaign, leaving north and west France, as well as the Low Countries, under Axis occupation. Territory was also ceded to Italy in the south. The remainder, Vichy France, consisted of south central France and most of the French colonies.

Battle of the Atlantic
The Battle of the Atlantic was a strategic campaign by Germany to enforce a naval siege of the United Kingdom. The primary German weapon was the U-Boat), although surface raiders, mine-laying craft, and aircraft also were used to attack Allied shipping and escorts in the Atlantic Ocean. The campaign extended into neighboring seas, such as the Caribbean Sea and North Sea, and even involved the Arctic Ocean and Indian Ocean, although the vast majority of engagements happened within the North Atlantic Ocean.  The campaign lasted for the duration of the war, and while Germany never succeeded in fully cutting off enough shipments to bring the United Kingdom into a negotiated settlement, the materiel cost to the Allies of lost shipments and effort exerted in defense of the convoys was significant, and therefore neither side clearly prevailed.

Strategic bombing campaign in Europe
After initial heavy losses and inaccurate bombings, RAF Bomber Command air raids against German military targets evolved to adopt nighttime attacks as their primary tactic in conjunction with a strategy of area bombardment against Nazi Germany morale. After the arrival of heavy bombers and the U.S. entry into the war, the Combined Bomber Offensive included daylight raids and attacks with formations of over 1000 bombers on German aircraft industry and vengeance weapon sites. The use of long range escort fighters using pressurized drop tanks (P-47s, July 1943) and navigation advances allowed increased bombing accuracy despite German radar-equipped night fighters and rocket interceptors. Significant Nazi Germany attempts to re-allocate fighters and flak guns to protect synthetic oil production during 1944 failed to stop the reduction in petrol supplies to German ground troops and aviation fuel to the Luftwaffe, nor the significant attrition of their experienced pilots. As a result, the Allies gained air superiority in late 1944 and air supremacy after the Luftwaffe was defeated in their Operation Bodenplatte counterair attack of January 1945.