The Holocaust

Why? Why did Hitler have to rise to power? Why did he treat human beings like he did? People are people. They are human. Jews are human, they are people. The same as Germans, Americans, Africans, Chinese. We are all people. Living, breathing people. Why couldn't Hitler see that? Why did he view Jews the way he did? We are all equal. At least, that's how everyone should be treated, like we are all the same. Why do these wars even start? Is it all because of one person, one group doing something completely stupid? Is it because of a leader trying to protect their nation? Why do these leaders feel the need to start a war between so many nation to protect their country? Are we not safe where we live? Why can't the countries just get along? I understand that I know nothing about politics, I know nothing about foreign trade. But, my one overall question for every country is, Why can't we all just get along?