The outbreak of World War 2 in Europe was not met by great enthusiasm by either side. Unlike World War 1 there was no nationalistic euphoria, as the realities of that war were still felt by many. With Poland invaded, the British and French policy of appeasement was no longer viable and the declaration of war was given on 3 September 1939. Against the expectations of the Nazis who were almost unbelieving that the Anglo-Franco partnership was actually abandoning their appeasement policy despite the promise of protection they had given to Poland. And so it was that war engulfed Europe once more.
At any rate, little was done to protect the Poles who were defeated by the speed and mobility of the German attack. Not to mention the overwhelming odds they faced. In actual fact, the Nazi-Soviet Pact made it very difficult for the French and British to commit themselves militarily.
With the Polish defeated, the war went quiet. So inactive it was actually becoming rather phony. The term Phony War was given to the period of military inactivity that followed. The French were more concerned with consolidating their Maginot line as opposed to offensive moves. Minor skirmishes at sea, the sinking of the German battleship the Graf Spee, gave the British more of a propaganda victory as opposed to a battle victory. Albeit, the Royal Navy had sunk one pocket battleship.
The Allies formulated a plan to cut off the German oil supplies in Sweden. This was the first real offensive action made by the Allies. Germany moved into and occupied Denmark on 10th April 1940 and the battle of Norway began. Poorly equipped Allied troops retreated, and the plan quickly became a defeat. German victory here gave them a better strategic position and ensured their oil supply. Equally, it was more significant for the Phony War was seemingly over.
On May, 1940, Germany invaded France by moving through and defeating the low-countries in addition to bypassing the French Maginot line. The offensive was again fast and mobile, with the Germans thrusting into Paris. The French mounted some rearguard action, but the British retreated its expeditionary force to Dunkirk. With Germany finishing off the French, Britain evacuated most of their troops from Dunkirk but lost much of their equipment. It was a serious defeat but ultimately the retreat had been a success. France became an occupied country, and Britain was left without allies. Equally, Italy now also entered the war by attacking British positions in North Africa in 1940.
A considerably stronger defensive barrier than the Maginot line saved the precarious position that Britain found itself in. Germany could not bypass the British Channel, and the RAF along with the Royal Navy would need to be dealt with to make an invasion possible. The Luftwaffe and RAF fighter planes engaged in the The Battle for Britain. German bombing of airfield proved to be damaging, but the decision to shift to bombing of cities a mistake as the RAF was able to recover. The RAF downed German bombers and fighters with sufficient number to ensure a narrow, but significant victory to Britain. Bombing continued but the run of German victories was over.
Italy engaging Britain in the Mediterranean also proved a blessing in disguise. For it enabled Britain to make sufficient enough gains, by defeating Italian armies in North Africa and the Mediterranean, to pose a strategic threat to Germany in the region. Thus, forcing Germany to commit troops to the area.
Despite this German victories in the Balkans, Crete and North Africa seemed reassuring enough for them to invade the Soviet Union (having had to postpone) on June, 22 1941. Significant for two reasons as Britain now had a surprising ally, and one with a large enough land army to fully engage Germany. The German advance, however, as far as the towers of Moscow left the USSR with much to contemplate. However, available reserves, strong winter weather and sufficient industrial strength enabled them to halt the advance and mount a counteroffensive by the end of the year.
Equally, Japanese bombing of Pearl Harbor on December 7, 1941 brought Japan into conflict with the USA (and Britain to lesser extent). The war between Japan and USA did not necessarily merit a German declaration of war on the USA. But they had been supplying Britain beforehand and helping in the Atlantic. As such, the declaration of war given by Germany formalized what had been before.
It ensured that unless the Axis (Germany, Italy and Japan) forced victory soon they would lose. For the resources the USA would bring, along with the USSR and Britain, gave the Allies a greater advantage that would ensure victory in the long-term. A second offensive, launched towards the oil fields in southern Russia in 1942, again pushed the Soviets back. However, at Stalingrad, despite their best efforts, Germany could not hold the city and surrendered. With Stalingrad lost, Germany entered into a steady run of defeats and retreat from the USSR.
Withdrawal of the submarine fleet from the Atlantic in 1943 left Germany's main hope for defeating Britain in tatters. In North Africa too, defeat at El-Alamein forced them out of the region allowing the Allies to engage and defeat fascist Italy in 1943 with German troops being tied up in the process. Effective Allied bombing on German cities limited Germany's industrial output despite the raising of the German economy to more of a wartime footing during 1942.
The success of Operation Overlord in 1944, which established a beachhead to liberate France, lifted the pressure on the USSR somewhat and left Germany in a hopeless position. Fighting America and Britain on land in France and the USSR in Eastern Europe. The last German offensive in 1944, at Ardennes, again surprised the Allies but could not be sustained. The Allies' movement towards Germany began in earnest. The USSR advanced and occupied Berlin, and the Allies moved into the Rhineland and Western Germany. On May 8, 1945 Germany surrendered unconditionally; and the Allies celebrated VE (victory in Europe) day. The war in Europe was over. In 1946, Japan surrendered, bringing World War 2 to a close.
The Axis lost the war in Europe for a number of reasons. Italy was an unreliable ally that required Germany to divert some troops away from the Eastern Front. Germany invading the USSR, while still at war with Britain, ensured a two front war for them. Their economy was on little more than peace-time setting prior to 1942. Ultimately, by engaging in war with America they had bitten off more than they could chew. The split resources required to fight on multiple fronts made it very difficult to force any sort of victory in the East or West and ensured their defeat.