The comparison and contrast of World War I (WWI) and World War II (WWII) causes have been for more than fifty years interesting topics of study. In addition, there are many causes of WWI and WWII, some similar and some different. I will discuss two similar and two major difference reasons for the outbreaks of the two wars.
The first reason of the wars is nationalism or the country's sense of pride and lust for power. In WWI, Germany wanted to expand its new boarders, strengthen their territory and challenge Britain to be the most powerful country on the planet. Germany had been created in 1871 and the German people had a building sense of pride for their new country. The same was true in WWII. Germany wanted to expand its empire throughout Europe, and have more 'living space'. The sense of national pride, which was tarnished by the War Guilt Clause from the Treaty of Versailles, needed to be fixed, and Hitler encouraged Nationalism emphatically.
The second reason of the two wars was the need for countries to acquire wealth and resources. In WWI and WWII, countries such as Britain, France, and other European countries looked elsewhere for rare treasures. In Africa, jewels like diamonds were mined, as well as gold in South Africa. Oil was another precious commodity from Africa and the Middle East. A point in both wars was the protection of Britain's trade routes.
There are countless differences in both wars, but the following two are good examples of such differences. Although imperialism played a part in both wars, the first was based more singularly on this point, as the second war was more about internationalism and imposing ideas on another people or country. WWI involved Britain and their colonial empire of India, Africa, and their other Asian areas more so than any other country. In WWII, it was more of a land grab. Hitler invaded Poland, Norway, then France and the Dutch and Denmark within the first year