saber rattling
A flamboyant display of military power; also, aggressive blustering. For example, There had been a great deal of saber rattling between the two nations but hostilities had never broken out . This term, originating about 1920 and alluding to an officer indicating he would draw his saber, at first referred to threatening military force but later was extended to more general use, as in Both candidates engaged in pre-debate saber rattling.