Wars and military escalations breed clichés that are exclusive, yet elusive. So the Vietnam War’s best and brightest spent a decade chasing their illusory “light at the end of the tunnel.” And today’s Situation Room strategists are turning each other into nodding but clueless bobbleheads every time they emptily say somebody just needs to create an “off-ramp” for Vladimir Putin. Everyone knows what everyone means: Just come up with a “face-saving” offer that Russia’s poker-faced president can accept — and avoid blundering ahead with the massive Ukraine invasion he now realizes could become an e…