"We are fighting a war in the FATA, we are fighting a war against terrorism," said Defense Secretary Leon Panetta on Wednesday, referring to the tribal areas of Pakistan that the U.S. has spent three years bombing heavily. Was that so hard to admit?

For years, it has been. Neither the Bush nor Obama administration has been forthright about the starkest fact of the recent war on terrorism: most of it takes place in western Pakistan. As CIA director and now Pentagon chief, Panetta has been one of the key architects of the accelerated drone-and-commando war the U.S. wages there in what amounts to an open secret. In 2009, the critical year in that acceleration, Danger Room boss Noah Shachtman started pressing the Obama administration for disclosure about a war the U.S. waged in all but name.

It may be late, but at least now it's happened. The day after the U.S. claimed that its latest drone strike in tribal Pakistan killed al-Qaida's second in command, Abu Yahya al-Libi, Panetta used the W-word to angrily dismiss the Pakistani government's complaints about the U.S. infringing on its sovereignty. "We have made very clear that we are going to continue to defend ourselves," Panetta said in New Dehli.

The war has remained undeclared for two reasons. First, it's awkward and potentially destabilizing to say Pakistan is a U.S. ally but the U.S. has to fight a war against terrorists on its soil. Second, it's politically perilous to ask a war-weary public to get used to fighting what's effectively a third war in a decade, even if this one relies far more on remote controlled robots than ground troops. That's suited the Pakistani government: it's given the U.S. tacit support for the drone strikes and enough cynical public denunciation of them to ward off popular upheaval. It's unknown how many civilians die in the drone strikes, but it's undeniable – except, sometimes, by the White House – that some do.

But that's gone out the window as U.S.-Pakistani relations have deteriorated over the past year. Pakistan kicked the U.S. out of an airbase used for the drone strikes and shut down a critical overland resupply route for the Afghanistan war. Panetta appears to be at his wits' end. His stark admission that the U.S. is at war in Pakistan followed a Tuesday tongue bath for Pakistan's arch-rival, India.

In case you're wondering, there aren't many legal implications or obligations prompted by Panetta's admission. The 2001 Authorization to Use Military Force, the legal wellspring of the war on terrorism, clearly authorizes attacking the perpetrator organization of 9/11 unbounded by geographic limits. Besides that, the short document is vague enough to fly a Predator through. There is little upside and much risk for any politician arguing it's time to end the 9/11 Era. To paraphrase Oliver Wendell Holmes, the life of the war has not been law; it has been politics.

It's hard to imagine the reverberations Panetta's comment will have amongst Pakistanis: polls indicate most don't realize there's a drone war going on at all. Americans are understandably preoccupied with domestic economic anxiety. The U.S. government, in other words, might have obscured its shadow war for nothing.