Mitt Romney personally responded to the Obama campaign’s outrageous Osama bin Laden ad this way: “Of course. Even Jimmy Carter would have given that order.” That’s fine, I suppose, but it’s defensive, and insufficient.

Here are four alternatives that would convey what’s shameful about Obama’s charge that Romney wouldn’t have ordered bin Laden’s assassination.

1. “Not only would I have ordered the hit, I would have ordered the enhanced interrogation techniques that led to his killing and saved many Americans. Jose Rodriquez, who oversaw the interrogation of Khalid Sheik Mohammed, told us on ‘60 Minutes’: ‘I am very secure in, in what we did and I am very confident that what we did saved American lives.’ Obama said he wouldn’t have allowed those interrogations.”

2. “Sure, I would have ordered it. And I would have kept interrogation procedures that allowed us to get valuable intelligence from terrorists. I’m all for killing terrorists by drones, but I sure wouldn’t want to lose the chance to get critical intelligence.”

3. “Sure, I would have ordered it. But really, how pathetic is it that the president of the United States is handed the intelligence and the game plan for killing Osama bin Laden, takes the layup and declares himself MVP?”

4. “Sure, I would have. The measure of a president isn’t his willingness to make the easy calls but to make the hard ones. On the Green Revolution, on bugging out of Iraq, on handcuffing our troops in Afghanistan, on slashing defense and much more, he’s not been willing to make the tough, unpopular calls to defend our national security.”

Regrettably, it seems that the Romney brain trust is content to let the president impugn their candidate’s character. A campaign doesn’t serve its candidate well by saying “Oh, no, our guy’s not a coward.” Playing it safe, playing not to lose is how you do lose on an issue and in an election.

The Romney team is right that the election will be mostly about the economy. But it will also be, as Romney himself has said, about leadership. That entails not merely batting away insults but driving the message home that, on both domestic and foreign policy, Obama isn’t up for the job.

Take, for example, the decision by the Obama team to sign off on a national security exception to anti-terrorism legislation, thereby releasing “$147 million for the Palestinian Authority at a time when P.A. President Mahmoud Abbas has demanded preconditions for returning to the negotiations while also pushing a unilateral statehood plan at the United Nations.” If the president concluded that a complete cutoff of funds would make it more difficult to influence the PA (I think this is rubbish, but reasonable people disagree), then why not release part of the money or condition it on action by the PA (e.g., separating itself from Hamas)? Where is the Romney campaign on this issue? (And no comment on the news that support for Obama among Jewish voters is down from 78 percent to 61 percent according to a new poll?) It’s not like the press is going to make Romney’s arguments for him.

Campaign operatives, especially those with no real experience or passion for foreign policy, no doubt counsel Romney to be cautious, selective and unprovocative in foreign policy. That would be fine if foreign policy under Obama was going swimmingly. But it’s not and it’s a potential source of weakness for him so long as Romney holds back. If caution gets the best of the Romney campaign, Obama’s liabilities on foreign policy will go unnoticed; Romney can’t afford to give him a free pass or to rekindle worries that he is a trimmer, not a leader.

UPDATE (2:10 p.m.): Maybe Romney should hire as his spokesman Arianna Huffington, who slaps down the president for the Osama bin Laden ad, calling it “one of the most despicable things you can do.”