Ten years ago, America invaded Iraq; somehow, our political class decided that we should respond to a terrorist attack by making war on a regime that, however vile, had nothing to do with that attack.

Some voices warned that we were making a terrible mistake — that the case for war was weak and possibly fraudulent, and that far from yielding the promised easy victory, the venture was all too likely to end in costly grief. And those warnings were, of course, right.

There were, it turned out, no weapons of mass destruction; it was obvious in retrospect that the Bush administration deliberately misled the nation into war. And the war — having cost thousands of American lives and scores of thousands of Iraqi lives, having imposed financial costs vastly higher than the war’s boosters predicted — left America weaker, not stronger, and ended up creating an Iraqi regime that is closer to Tehran than it is to Washington.

So did our political elite and our news media learn from this experience? It sure doesn’t look like it....