This is not “just another” terror attack, or “just another” round of unrest and repression in the Middle East. This is a NATO country, increasingly divided and anti-Western, careening between two dark futures with no end in sight and no peaceful escape from a showdown. Here in a single paroxysm is fodder for every one of Trump’s indictments against the U.S.-led international “order”: the passivity, weakness, and irrelevance of the Obama administration and the North Atlantic alliance at their worst; the implacable strength of Muslim extremists in the absence of effective local strongmen; the absurdity of depending on weak regional partners while rejecting grand bargains with those who can best project power; and perhaps above all, the profound lack of wisdom of trying to “lead” a hostile and alien world engaged in a bloody and uncontrollable race to the bottom.

There are, of course, counterarguments — some immensely prudent, others drawing on principles without which American foreign policy would itself become hostile and alien. But the essence of Trump’s worldview hinges on its supposed self-evidence, and Turkey’s ragged coup makes America’s traditional, deepening anti-globalism feel like common sense. There again are the crowds, the tanks, the videotaped statements, the threatened airports, the lockdowns, the gunfire. There again is the virus of disorder spreading across the rest of the West. What, possibly, could we do about it that would be worth the terrible cost? The American hurdle for liberal internationalism, and therefore Hillary Clinton, has just ratcheted much higher.

It has risen higher, indeed, than Trump’s more overheated fans and critics had imagined that Brexit would raise it.