How did World War 1 connected to World War 2?

Answer 1

WWII could be considered a direct result of WWI.

The problem with WWI is that the peace treaties and surrender statements forced upon Germany were substantial and blamed the war 100% on Germany, forcing them to repay all war-related debts. This was known as the "War-Guilt Clause". The Treaty of Versailles, which was supposed to end the war, but in reality, cause much debate: the U.S. never even agreed to it!

With upset German natives in the military (such as the young Adolf Hitler), they felt very angry with the blame of the War and ultimately led them to retaliate, thus causing WWII.

Answer 2

World War I was connected to WWII because the Treaty of Versailles made Germany fall into The Depression. Then Hitler took control of Germany as dictator and lead the invasion of Poland which lead to World War II.