The British army wanted Indian lands which caused the war
Higher level party leaders (Hitler) which he was a dictator but still he had the all control over that area
They made the European community unite against Napoleon.
One the one hand , we have the revolutionary vision of Napoleon of bringing new ideas into neighbouring and distant European nations. Napoleon himself declared_"I wished to found a European system...a European Code of Laws, ..: there would be but one people in Europe," With the Napoleonic Wars, the nations had to assemble in order to balance power, thus, giving birth to famous treaties and conventions such as the Treaty of Paris and Vienna. With increasingly many political opponents, the Europeans tried to banish the specter of Napoleon and its influence so either from the perspective of Napoleon or his opponents, a common European space was born.
The first World War ended with the Treaty of Versailles, which ruined all of what Germany had gained from the war. Included was that Germany couldn't have an army of any great size nor power, large portions of the territory gained was taken, it forced Germany to pay for the damages which were caused, and to admit that the war itself was Germany's fault. Each part of this Treaty angered Germany. So when the Nazi's became popular, it appeared that the Nazi's (who were fascist) might be able to abrogate the treaty and Germany to what they thought was its rightful place as a major power, the Germans supported them.