Mitt Romney on Tuesday ate cheese pizza with firefighters and held a news conference to declare that he would be a tough commander in chief.

At the same moment, President Obama was aboard Air Force One on a secret trip to Kabul, putting the finishing touches on an address to the nation marking the first anniversary of the Osama bin Laden raid he oversaw.

The contrast was both a testament to the power of incumbency and a fresh illustration of one of the more difficult challenges Romney confronts as the GOP’s presumptive presidential nominee: to press the case that Obama is weak abroad despite having ordered the raid that killed the world’s most-hunted terrorist.

So far, Romney is responding to the challenge in a nuanced manner. Flanked by former New York mayor Rudolph W. Giuliani on the sidewalk outside a firehouse that lost 11 first responders on Sept. 11, 2001, Romney first congratulated Obama for authorizing the attack on bin Laden.

But Romney also acknowledged the intelligence officials who worked for years to determine bin Laden’s whereabouts as well as the members of Navy SEAL Team 6 who executed the risky, overnight mission into Pakistan.

Romney’s message was subtle yet clear: Obama deserves some credit, but hardly all of it.

As the former Massachusetts governor said earlier on “CBS This Morning,” “any thinking American would have ordered the exact same thing.”

Romney has been on the defensive this week in responding to suggestions by Obama’s political team that he would not have issued the same order to kill bin Laden if he had been president.

In an interview Tuesday, Eric Fehrnstrom, a senior adviser to Romney, accused Obama of “taking an event that united Americans and using it to divide us.”

“A year ago, the president said the death of Osama bin Laden was not an occasion for spiking the ball,” Fehrnstrom said. “He’s not only spiking it, but he’s put it on a float and is parading it down Pennsylvania Avenue.”

Fehrnstrom charged that by raising the killing of bin Laden as a campaign issue, Obama was trying to distract voters from “his wider failures on foreign policy” – including, he said, missile defense negotiations with Russia as well as handling North Korea’s and Iran’s pursuit of nuclear weapons.

Obama’s campaign last week released a video narrated by former president Bill Clinton, who testified to the president’s leadership in giving the order to kill bin Laden. Obama also sat for an interview with NBC News, looking back on the decision.

“I hardly think that you’ve seen any excessive celebration taking place here,” Obama said at a news conference Monday.

Obama accused Romney of contradicting his own earlier statements by saying he would have made the same decision as Obama given the same intelligence. Obama did not mention Romney by name, but he may have been referring to Romney’s 2007 comment that he did not believe it was “worth moving heaven and earth and spending billions of dollars just trying to catch one person.”

When reporters pressed Romney on Tuesday to square the discrepancies, the candidate responded by invoking Vice President Biden, who as a candidate in the 2008 Democratic primaries said of then-rival Obama that he would be “naive” to announce in advance that he would go into Pakistan.

“Many people believed, as I did, it was naive on the part of the president at that time the candidate to say he would go into Pakistan,” Romney told reporters. “It was a very, if you will, fragile and flammable time in Pakistan, and I thought it was a mistake of his as a candidate for the presidency of the United States to announce that he would go in.”

With that, Romney tried to pivot back to a core argument he has been making on the campaign trail: that Obama is a naive leader who is in over his head in the Oval Office.

But with the bin Laden anniversary dominating the day, Romney’s message was quickly lost. Within an hour of Romney’s remarks, news broke that Air Force One had touched down in Afghanistan, and the networks prepared to air Obama’s speech to the nation.