President Trump’s demand of “unconditional surrender” by the Iranian regime is both absurd and terrifying.

It is absurd because history’s examples of unconditional surrender mostly have followed brutal destruction — Dresden, Hiroshima, Nagasaki — quite unlike the narrowly targeted strikes that the U.S. and Israel have launched on Iran. And it is terrifying because the president’s grand delusions just might march us down that road to Armageddon.

Beyond courting that calamity, the U.S. attacks on Iran violate a hallowed principle of international law. The U.N. Charter allows attacks on sovereign nations in only two cases — if authorized by the U.N. Security Council or in self-defense after an armed attack. Because waiting for an armed attack can prove disastrous, international law has long countenanced “anticipatory” self-defense to ward off imminent attacks, a standard most experts say prevails under the charter today.

This principle of imminence found a prominent champion in Daniel Webster, who twice served as Secretary of State in the mid-19th century. After the British justified an attack on U.S. territory as an act of self-defense, Webster delivered a famous riposte. Self-defense can justify one nation’s invasion of another, he wrote in 1842, only if the “necessity of that self-defence is instant, overwhelming, and leaving no choice of means, and no moment for deliberation.” Modern proponents of a right of anticipatory self-defense have........

© The Hill