"This is the kind of brinksmanship you get when leaders of a rogue regime are under growing pressure. The only hope to get them to reverse course is to relentlessly increase their feeling that, if they don't, the Arab states, Israel, the Europeans and America will, one way or another, ensure that ruin is visited upon them."
He's talking about how Iranian president Ahmadinejad recently claimed that the US and Israel were planning on attacking two Mideastern countries soon. How exactly this represents "brinksmanship" on Ahmadinejad's part is a little unclear -- he's not, after all, threatening any attacks, he's claiming others are doing so -- but even more startling is Krauthammer's prescription: Since the pressure on Iran is making the president crazy and reckless (as Krauthammer's sees things), the solution is... even more pressure!
Of course, for Krauthammer, the solution to every foreign policy difficulty is for America to adopt a more belligerent stance, I guess that shouldn't really surprise me.