The first conventional Washington rule about nuclear strike policy is that you don't talk about nuclear strike policy.
The second conventional Washington rule about nuclear strike policy is that when you are forced to talk about nuclear strike policy, you respond with a variant of "All options are on the table."
Some comments of Barack Obama today reached critical mass by late afternoon. When the AP first reported that Obama had said he would never use nuclear weapons, the context was unclear. And so was his answer, which included a pause and then the addition: "involving civilians." And then he tried to scratch his entire answer. So -- was Obama announcing to the world that the United States would never use its stockpile of nuclear weapons? Unilateral disarmament? Turns out that the AP story failed to add a very important bit of context. Obama was asked about using nuclear weapons against terrorist targets Afghanistan and Pakistan; the Bush Administration has never ruled out using tactical nukes to root out underground terrorist safe havens. In this much more limited context, Obama was setting some policy: no, he would not ever consider using nuclear weapons on terrorist targets in those two countries.
Still, he violated Rule 1 and Rule 2, which drew a response from Sen. Hillary Clinton.
"Presidents should be very careful at all times in discussing the use or non-use of nuclear weapons," Clinton said. "Presidents since the Cold War have used nuclear deterrence to keep the peace. And I don't believe that any president should make any blanket statements with respect to the use or non-use of nuclear weapons."
There's no question that Obama ought to have been more careful with his words. That, when he's asked about using nuclear weapons, his mind immediately sends words to his mouth is evidence that his internal monitor developed outside Washington.
The Clinton campaign will use this story to further a narrative about Obama -- that he is too inexperienced to handle radioactive national security questions.
The Obama campaign might use this story to reinforce its own efforts to draw distinctions between the Old Ways Of Washington and the New Way Of Obama.