Nazi Germans murdered a bunch of Jews and disabled people for the sole purpose of having a superior Aryan race. The violence towards these people ruined the way the country was viewed on how they treat people. The mass killings that occurred in concentration camps was not justified for this large number of people.
Violence was never justified to all these families that where involved in the greatest war of history. Children were in fear that they were going to lose their families in the second world war. Children could get involved by being a messenger or sewing for troops. By being so close to fighting the children were in danger.
This video talks about all of the major battles that happened in World War 2. Like in Germany and Britain. In the battles, each country lost a lot of soldiers but managed to succeed some of the battles with victories. Each victory gets them closer to meeting their goals, which for some was to gain more control of other countries while other countries were trying to stop them from gaining more control.
Hitler did not plan to take over the world. He wanted Vikings, German and Northern European to live in Eastern Europe. Northern Africa was only invaded as a way to help the European strategy. A different way for a plan of attack was to keep the Suez canal open so they could get materials to Russia.
Many people say violence is never good to settle arguments. However, if you oppose violence in riots you also need to be opposed to violence in wars. There are more deaths in wars than riots and more support war. It is a common thing to say "violence doesn't solve anything" but it does in some reasons like if one country's says that they do not have enough space and they attack another country and are successful then they solved their problem.
In World War 2 it was the Germans goal to take over Western Europe and then the Soviet Union. In order to meet the goal they needed to take over these countries and use violence to solve their problems. This caused the US to join the war against the Germans which led to even more violence.
The total cost of all countries involved in the war was high. The total cost for the countries that were fighting with Germany was less than the overall total cost for the countries on the other side of the war. This shows the economic cost of war on countries.