Question

The first world war,or the war to end all wars broke out in 1914 .however ,tensions in europe had been building up since [*when*]

Answer 1

World War I was known as the “war to end all wars” because of the great slaughter and destruction it caused. Unfortunately, the peace treaty that officially ended the conflict—the Treaty of Versailles of 1919—forced punitive terms on Germany that destabilized Europe and laid the groundwork for World War II.