Answer:
Like the previous answer stated The Great Depression, Treaty of Versailles, among other factors. The Treaty of Versailles basically screwed over Germany and it left it vulnerable enough for monsters like Hitler to manipulate the nation, and I don't think The Great Depression needs an introduction. Rises in nationalism was among the other factors, and that's what Hitler used to come to power in Germany, and believe it or not, it took a really loooong time for him to come power. Italy and Japan also joined up with Germany because of rises in nationalism and the opportunity to become a world power back then didn't sound so bad for Japan. Rise in militarism also contributed to it, with numerous nations in an arms race to outcompete the others, and as you could imagine, this led to conflicts. There's a bunch of more reasons but I think they would be too lengthy for a brainly answer.
Explanation:
For this to start it was awfully hard.
