This matters. So much of geopolitics is a matter of credibility. Some forces, unfortunately, only understand the language of uncompromising strength. We supposedly learned that again after the attack on the USS Cole. But here we are, mourning American dead while their killers walk free. It makes us look weak. It undercuts the idea of justice. And every day that goes by makes justice more difficult to attain, as the attack recedes in the rearview mirror of history.

No doubt, that is not the intention of the Obama administration. But it is the effect. There is every reason to feel a sense of urgency. After four months, however, a sense of urgency seems to be absent. It is in the president’s power to prove us all wrong and remind the word that America never forgets. But the clock is ticking, and every day the credibility gap grows.

We cannot know just how terrorists might be emboldened by the idea that they can kill Americans without painful retaliation. But it cannot be a positive precedent. Al Qaeda and its offshoots “do not have the operational planning capability right now to pull off a 9/11-type attack,” said Lippold. “But if [the Obama administration] does nothing to respond to these attacks, they will regroup, find a safe haven, and then they will find that capacity, and they will come after us again.”