I thought the third and last presidential debate was a clear win for the President. He displayed the authority of the nation’s Commander-in-Chief – calm, dignified, and confident. He was assertive without being shrill, clear without being condescending. He explained to a clueless Mitt Romney the way the world actually works.

Romney seemed out of his depth. His arguments were more a series of bromides than positions – “we have to make sure arms don’t get into the wrong hands,” “we want a peaceful planet,” “we need to stand by our principles,” “we need strong allies,” “we need a comprehensive strategy to move the world away from terrorism,” and other banalities.

This has been Romney’s problem all along, of course, but in the first debate he managed to disguise his vacuousness with a surprisingly combative, well-rehearsed performance. By the second debate, the disguise was wearing thin.

In tonight’s debate, Romney seemed to wither – and wander. He often had difficulty distinguishing his approach from the President’s, except to say, repeatedly, “America needs strong leadership.”

On the few occasions when Romney managed to criticize the President, he called for a more assertive foreign policy – but he never specified exactly what that assertiveness would entail. He wanted “tougher economic sanctions on Iran,” for example, or “stronger support for Israel” – the details of which were never revealed.

Obama’s most targeted criticism of Romney, on the other hand, went to Romney’s core weakness – that Romney’s positions have been inconsistent, superficial, and often wrong: “Every time you’ve offered an opinion,“ said Obama, "you’ve been wrong.”

Nonetheless, I kept wishing Obama would take more credit for one of the most successful foreign policies of any administration in decades: not only finding and killing Osama bin Laden but also ridding the world of Libya’s Gaddafi without getting drawn into a war, imposing extraordinary economic hardship on Iran, isolating Syria, and navigating the treacherous waters of Arab Spring.

Obama pointed to these achievements, but I thought he could have knitted them together into an overall approach to world affairs that has been in sharp contrast to the swaggering, bombastic foreign policies of his predecessor.

Like George W. Bush, Mitt Romney has a pronounced tendency to rush to judgment – to assert America’s military power too quickly, and to assume that we’ll be viewed as weak if we use diplomacy and seek the cooperation of other nations (including Russia and China) before making our moves.

President Obama won tonight’s debate not only because he knows more about foreign policy than does Mitt Romney, but because Obama understands how to wield the soft as well as the hard power of America. He came off as more subtle and convincing than Romney – more authoritative – because, in reality, he is.

Although tonight’s topic was foreign policy, I hope Americans understand it was also about every other major challenge we face. Mitt Romney is not only a cold warrior; he’s also a class warrior. And the two are closely related. Romney tries to disguise both within an amenable demeanor. But in both capacities, he’s a bully.