"Romney made a strategic decision not go after the president on Libya, or Syria, or other areas where Obama could accuse him of being a Bush-like war monger."

Observed Charles Krauthammer — aptly, I think.

Obama didn't get much to fight against, and as the debate wore on, perhaps Obama worried that he might seem too much like the Obama who lost the first debate. Live-blogging, half an hour into the debate, I wrote: "They've stopped interrupting each other. No belligerence tonight. There's an evenness and similarity to the 2 candidates." 5 minutes later, Obama suddenly got really belligerent. That was odd. I'm thinking he decided he had to tear Romney down even if Romney gave him no useful material. Romney stuck to his game of giving Obama nothing, so Romney "won" by his own terms. He won the game he chose to play, and he didn't get distracted into playing Obama's game, though Obama tried to aggravate him.

Ironically, assuming Krauthammer is correct, Obama wanted belligerence (at the debate) about Romney's belligerence (in the world). Romney declined to be that belligerent — Bush-like! — guy Obama wanted to be belligerent with. Romney deprived him of the casus belli, but he went to war — the war of the debate table — nonetheless.

I'm looking at the transcript. What was going on when Obama suddenly broke the debate's placidity? The candidates were in the middle of chewing over the most abstract question of the night: "What do each of you see as our role in the world?" Most of the questions last night were, essentially, the naming of a country: Libya, Syria, Pakistan.... This was the big-picture question. Romney did his 2 minutes, which included a section about the American economy:

[To lead in the world], we have to strengthen our economy here at home. You can't have 23 million people struggling to get a job. You can't have an economy that over the last three years keeps slowing down its growth rate. You can't have kids coming out of college, half of them can't find a job today, or a job that's commensurate with their college degree. We have to get our economy going.

Obama's response included some domestic economics:

But what we also have been able to do is position ourselves so we can start rebuilding America, and that's what my plan does. Making sure that we're bringing manufacturing back to our shores so that we're creating jobs here, as we've done with the auto industry, not rewarding companies that are shipping jobs overseas.

Making sure that we've got the best education system in the world, including retraining our workers for the jobs of tomorrow.

Doing everything we can to control our own energy. We've cut our oil imports to the lowest level in two decades because we've developed oil and natural gas. But we also have to develop clean energy technologies that will allow us to cut our exports in half by 2020. That's the kind of leadership that we need to show.

And we've got to make sure that we reduce our deficit. Unfortunately, Governor Romney's plan doesn't do it. We've got to do it in a responsible way by cutting out spending we don't need, but also asking the wealthiest to pay a little bit more. That way we can invest in the research and technology that's always kept us at the cutting edge.

That seems like way too much domestic policy, but maybe Obama realized that the election really is going to be about the economy. He wasn't getting any traction on the foreign policy material that is supposedly the topic of this third debate, and this is the last debate. The election won't be won or lost on who stuck to the foreign policy theme, and anyway, Romney started it. But Obama must have also realized that he was going on, as if on autopilot, and not addressing the big-picture question of the night: What does he see as our role in the world? The vision thing!

If "vision thing" doesn't ring a bell for you, here's the "Vision thing" Wikipedia article:

In the January 26, 1987, issue of Time magazine, in an article entitled “Where Is the Real George Bush?” journalist Robert Ajemian reported that a friend of Bush's had urged him to spend several days at Camp David thinking through his plans for his prospective presidency, to which Bush is said to have responded in exasperation, "Oh, the vision thing." This oft-cited quote became a shorthand for the charge that Bush failed to contemplate or articulate important policy positions in a compelling and coherent manner.

Obama collected his wits and, with a few seconds to go on the vision-thing answer, he said:

Now, Governor Romney has taken a different approach throughout this campaign. Both at home and abroad, he has proposed wrong and reckless policies. He's praised George Bush as a good economic steward and Dick Cheney as somebody who's - who shows great wisdom and judgment. And taking us back to those kinds of strategies that got us into this mess are not the way that we are going to maintain leadership in the 21st century.

The vision is: Bush was terrible! The familiar word string "got us into this mess" dribbles out of Obama's mouth for the thousandth time. I'm not Bush — that's the vision, and even though Romney failed — as Krauthammer pointed out — to be enough like Bush to give Obama a place to stand and declare I AM NOT BUSH, he did it anyway.

Schieffer turned to Romney and repeated the words "wrong and reckless policies." (Schieffer was brilliant, by the way. So minimal and unobtrusive, but absolutely there.) "I've got a policy for the future and agenda for the future," Romney said, launching away from the question and into his 5-point plan for the economy. He's not Bush either, and he doesn't bother to explain why. If the question was supposed to be about Bush-and-Cheney's warmongering, Romney ignores that. Obama responds using his 2 minutes to talk about the economy too — not to refocus us on Bush's belligerence. After the 2 men have consumed approximately equal time in this off-topic speechmaking, Schieffer breaks in:

SCHIEFFER: Let me get back to foreign policy.

(CROSSTALK)

SCHIEFFER: Can I just get back...

ROMNEY: Well - well, I need to speak a moment...

SCHIEFFER: OK.

ROMNEY: ... if you'll let me, Bob, just about education...

SCHIEFFER: OK.

Okay!

ROMNEY: ... because I'm - I'm so proud of the state that I had the chance to be governor of. We have every two years tests that look at how well our kids are doing. Fourth graders and eighth graders are tested in English and math. While I was governor, I was proud that our fourth graders came out number one of all 50 states in English, and then also in math. And our eighth graders number one in English and also in math. First time one state had been number one in all four measures. How did we do that? Well, Republicans and Democrats came together on a bipartisan basis to put in place education principles that focused on having great teachers in the classroom.

And here's where Obama goes for the interruption that broke the mood of placidity last night:

OBAMA: Ten years earlier...

ROMNEY: And that was - that was - that was what allowed us to become the number one state in the nation.

OBAMA: But that was 10 years before you took office.

(CROSSTALK)

[OBAMA]: And then you cut education spending when you came into office.

ROMNEY: The first - the first - the first - and we kept our schools number one in the nation. They're still number one today.

SCHIEFFER: All right.

ROMNEY: And the principles that we put in place, we also gave kids not just a graduation exam that determined whether they were up to the skills needed to - to be able compete, but also if they graduated the quarter of their class, they got a four-year tuition- free ride at any Massachusetts public institution of higher learning.

OBAMA: That happened before you came into office.

SCHIEFFER: Governor...

ROMNEY: That was actually mine, actually, Mr. President. You got that fact wrong.

(CROSSTALK)

SCHIEFFER: Let me get - I want to try to shift it, because we have heard some of this in the other debates.

As I put it last night, "Obama just did some sharp interrupting while Romney was rhapsodizing about education in Massachusetts." To restate my observation: Obama suddenly changed his tone, got belligerent, when Romney was just going on innocuously about education. There was no casus belli. Whatever happened happened inside Obama head. I need to be Debate #2 Obama, not Debate #1 Obama. He felt the placidity of the evening, the utter failure to ignite the BUSH!!!!! petard, so he made a fight out of nothing.