Campaigns of World War II The campaigns of World War II were the military operations that were employed during World War II . Campaign s generally refer to broader strategic operations conducted over a large bit of territory and over a long period of time . Battle s 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 . Strategic campaigns . 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 raider s , 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 raid s 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 bomber s 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 .