How did isolationism play a role in causing World War II? It allowed the Chinese to divide Japanese forces into many smaller parts, attacking and defeating them one by one.

It gave Japan the freedom to conquer territory through Asia without interference from the United States.

It singled out France as the only free nation left in Europe after the fall of Poland to the Germans, leaving it to face Germany alone.

It shielded the German army from opponents after its invasion of France, allowing them the chance to withdraw after being defeated.