Now the Republican presidential candidate who is the front-runner for the nomination among those whose name is not Trump has joined in the promoting of the Iraq War myth. The twofer becomes a threefer, with the added motivation being that it is a way of attacking the front-runner for the other party's nomination, the idea being that she somehow should have done more to fix Iraq while she was secretary of state. Or maybe it is a fourfer, given that it is a way of dealing with the political liability that association with his brother's war is for Jeb Bush. So expect to hear more of this in the coming months of campaigning.

Hiatt's concluding application of his “lesson” about military force to the Iran agreement is that insufficient brandishing by Obama of the threat of military attack means Iran has not made as many concessions at the negotiating table as it otherwise would have. The Iranians, upon hearing this sort of contention, probably wonder whether, as far as lessons from the Iraq War are concerned, most Americans think the way Hiatt is thinking and whether disinclination to start another Middle East war is just a matter of wimpiness on the part of Barack Obama. Whether the Iranians wonder that or not, we should wonder why anyone should expect that a threat of armed attack would make the Iranians any more inclined to accede to U.S. demands on points on which the Iranians have shown firmness for reasons of pride, sovereignty, credibility, and internal politics. We should especially wonder that about a nation that endured what the Iranians endured with stoicism and determination for eight years the last time someone else attacked them. Hiatt also needs to explain how threats of military attack are supposed to reduce, rather than increase, any remaining Iranian interest in developing a nuclear deterrent, the very purpose of which would be to ward off such attacks.

Yes, let us not establish one-issue litmus tests. But let's use the evidence from recent experience to identify where sound judgment has existed and where it has not. And as we draw lessons let's make sure they are the right ones.