Explain why Germany was successful in the Second World War up to the end of 1941, but suffered ultimate defeat in 1945.

By the end of September 1939, Germany and Russia had occupied Poland. After five months Germany without much resistance occupied Denmark and Norway. Major successes came in May when Belgium, France and Holland were knocked out of the war. Many reasons can be attributed to these initial successes of Germany:

• German doctrine of Blitzkrieg (lightning war). First introduced in the Poland campaign. It involves rapid thrust of motorized division and tanks. Supported by Luftwaffe (the German Air Force).
• Most important event was the defeat of France. France at the time of war was internally divided between Left and Right. Thus France was psychologically not prepared for war. There were also many military weaknesses and wrong decisions.
• Another decision which gave German free hand was French inaction during their Poland campaign. If French had launched the attack on Germany at that time things might have come out differently.
• Most important factor was that USA and USSR were still out of the war. It was important as they both were resource rich and all the countries Hitler had occupied were all small except France (whose reasons for defeat are mentioned above).

However, things started to change after 1941 due to some decisions and strategic mistakes:

• The first mistake was not defeating and occupying Britain. This resulted in constant air raids on German cities and industrial centres. Later she was used as the launching pad for Allies on D-Day (Operation Overlord).
• The German invasion of Russia (Operation Barbarossa) was ill planed and all the factors were not taken into account, especially Russian winters. When Russian winter arrived German army was caught ill-prepared. German Generals miscalculated the Russian strength to fight.
• German declaration of war on the USA after the Japanese attack on Pearl Harbour. This was perhaps the most serious mistake on the part of Hitler. Now that Germany was unlike before 1941 was fighting against resource rich nations like the USA, USSR and Britain with its colonial resources at the same time.
• German brutal behaviour towards occupied populations which they used to consider as second class peoples. This made population to hate Nazi rule.
• As the war stretched longer Germany was no longer able to match the military production of Allied powers. And on that constant harassment by Allied Air Force by targeting German military industries.
• Shortage of raw materials due to Allied blocked.

With Germany fighting on multiple fronts and over above lack of resources to meet troops requirement lead to ultimate German defeat.    

Topics: GS-I: World Wars, Cold War and Other Major Events of 20th Century