false flag

A covert operation, military or otherwise, which attempts to present a different identity of the perpetrators, for propaganda, diplomatic or strategic reasons. The casus belli of the 1939 German invasion of Poland was the attack on the German Gleiwitz radio station by “Polish nationals” who were, in fact, disguised Gestapo members. Term derives from pirate ships who would fly flags of friendly countries so as to entice target ships.