During this week of retrospectives on the killing of Osama bin Laden, one of the most interesting public comments was White House counterterrorism chief John Brennan's speech formally affirming that "the United States government conducts targeted strikes against specific al-Qaida terrorists, sometimes using remotely piloted aircraft, often referred to publicly as drones."

Well, everyone knew that, right? Yes, the drone program was indeed very well known - perhaps the world's worst-kept secret. But until Brennan's speech Monday, it was not officially acknowledged. He was, in effect, outing what had been a "covert action" program conducted by the CIA. Not only that, he also explained some of the rules guiding the White House when it decides to kill adversaries under this program.

Brennan made some laudable points in his speech but also some puzzling ones. But what troubles me about the speech is that it further politicizes this realm of national-security policy - making it easier for President Obama's team, and the president himself, to talk publicly about the drone war in the coming campaign.

Since the program is no longer secret, Obama's surrogates can now brag about it all they want. Not only did Obama authorize the raid that killed bin Laden, his campaign advisers can say. Thanks to Obama's aggressive drone attacks, "the core al-Qaida leadership is a shadow of its former self," to quote Brennan's words.

Brennan described the rationale: "I'm here today because President Obama has instructed us to be more open with the American people about these efforts." And certainly, there's a good public-policy argument for greater disclosure. With many other analysts, I've argued for a broader debate about drones to establish sound rules for their use.

"There needs to be a public vocabulary for this subject," contends Benjamin Wittes, one of the founders of the Lawfare blog that examines national-security legal issues. "Whether they've got all the details of the framework right is a very hard question, but I'm admiring of the basic instinct to describe it in public."

Open debate about drone policy is valuable. I just wish Brennan hadn't expanded it at the very time Obama's political advisers are preparing to run partly on his tough-minded role as "covert commander in chief," as I described him in a column last year. As these politicos plan the campaign, they see Obama's victory in the "mano-a-mano" duel with bin Laden (who wanted, equally, to kill the president) as one of his best issues.

Looking at the details of Brennan's speech, I found several aspects confusing - and indicative of why more public debate is needed.

One knotty issue is the legal standard for these targeted killings (or, to use a less euphemistic term, assassinations).

Brennan says the president has general constitutional authority as commander in chief to act against "any imminent threat of attack," and a specific congressional mandate to strike any member of al-Qaida, under the 2001 Authorization for Use of Military Force. But with al-Qaida members, Brennan goes on, "when considering lethal force we ask whether the individual poses a significant threat to U.S. interests." Except when the al-Qaida member is a U.S. citizen; then the standard narrows to "whether the individual poses an imminent treat of violent attack."

Maybe administration lawyers understand the legal and practical differences between "imminent" and "significant," but I don't.

Then there's the question of international legal authority. Brennan argues that drone attacks for self-defense are legal under international law, "at least when the country involved consents or is unable or unwilling to take action against the threat." Now where, I wonder, does Pakistan fit under that standard? It used to "consent" secretly, but is it now "unwilling" or "unable," or some hybrid?

The bedrock problem, as Brennan rightly notes, is that America is setting standards for a world in which dozens of countries will soon have drones. What if the Chinese deployed drones to protect their workers in southern Sudan against rebels who have killed them in past attacks? What if Iran used them against Kurdish separatists they regard as terrorists? What if Russia used them over Chechnya? What position would the U.S. take, and wouldn't it be hypocritical if it opposed drone attacks by other nations that face "imminent" or "significant" threats?

Ducking these questions was easier when drone attacks were part of a covert CIA program whose existence was officially denied by the U.S. government. But that status ended Monday, and we're just beginning the process of finding good answers.