Pretexting

Remember how WW2 started? The Germans felt "compelled" to mount a military response to the dastardly, unprovoked "attack" by the Polish army on a radio station just over the German-Polish border. Shortly thereafter we were treated to scenes of mounted Polish cavalry riding with lances poised into the teeth of Nazi panzer units and machine guns.

Remember the Maine?

How about the Turner Joy?

Kristallnacht?

Warmongers have occasionally felt the need for a pretext. They have never wanted for one, even if it had to be manufactured out of whole cloth.