One first impression left by President Obama’s much-anticipated speech re-casting U.S. counterterrorism policy is that of the contrast between Bush’s swagger and Obama’s anguish over the difficult trade-offs that perpetual war poses to a free society. It could scarcely be starker. While Bush frequently seemed to take action without considering the underlying questions, Obama appears somewhat unsure of exactly what actions to take. That is not a bad thing: at least he is asking the right questions. In fact, by suggesting that, after a decade and seven thousand American and countless foreign lives lost, and a trillion dollars spent, it might be time to start downsizing the “war on terror,” he is leading the national debate beyond where even most Democrats have dared to go.

The two Presidents seem to have fundamentally different starting points about how much can be achieved by the exercise of U.S. force. Bush seemed to think it possible that America could expunge evil around the globe—he declared war on what he called the “Axis of Evil,” and announced, shortly after September 11, 2001, “Our war on terror begins with Al Qaeda but does not end there.” Obama, in contrast, conceded that the elimination of evil in general, and terrorism in particular, was beyond the scope of any politician or nation. As he defined it, the struggle against evil was part of the human condition, not an enemy suitable for armed warfare.

“Neither I, nor any President, can promise the total defeat of terror,” Obama said. “We will never erase the evil that lies in the hearts of some human beings, nor stamp out every danger to our open society.” As Obama expressed it, “We must be humble in our expectations.”

Obama agonized over other limitations, too. Bush’s lawyers propounded the astonishingly radical theory that, as Commander-in-Chief, a President couldn’t be limited by domestic or international law. His lawyers dubbed it “the New Paradigm” and reasoned that if national security was at stake, no other legal constraints could stand in the President’s way. The Geneva Conventions became optional, cast aside as “quaint.” Obama embraced both constitutional and international legal limits, at least in principle, even as he struggled to define them in practice. In fact, his speech was a paean to the theory of “just war,” which requires a balance between means and ends, demanding proportionality whenever the state resorts to the use of force. It’s a sophisticated and nuanced moral theory, on which the law of conflict rests. Obama has openly grappled with the most difficult questions posed by the most serious thinkers in this area.

Obama’s public acknowledgement of his armed drone program, and willingness to subject it to tighter scrutiny and oversight, won’t satisfy his most persistent critics. Indeed, shortly after the speech, Anthony D. Romero, executive director of the American Civil Liberties Union, released a statement criticizing what he called the program’s “insufficient transparency,” adding, “We continue to disagree fundamentally with the idea that due process requirements can be satisfied without any form of judicial oversight by regular federal courts.”

Yet here, too, Obama’s evident pain over the program, whose civilian deaths he said would “haunt” him and his command “as long as we live,” seemed a telling change from the secrecy and winking smugness of the past. So was Obama’s admission that just because the United States has the technical prowess to incinerate its enemies halfway around the world doesn’t automatically mean that there is a moral basis for doing so. “As our fight enters a new phase, America’s legitimate claim of self-defense cannot be the end of the discussion,” Obama said. “To say a military tactic is legal, or even effective, is not to say it is wise or moral in every instance. For the same human progress that gives us the technology to strike half a world away also demands the discipline to constrain that power—or risk abusing it.”

He went on to acknowledge that drones have their limits, and that “force alone cannot make us safe.” Instead, he called for a “conversation about a comprehensive strategy” to “reduce the wellsprings” of radicalism, one that uses not just hard power but soft power, such as foreign aid, education, and support for transitions to democracy in the Arab world and peace in the Middle East:

Our systematic effort to dismantle terrorist organizations must continue… But this war, like all wars, must end. That’s what history advises. That’s what our democracy demands.

Obama’s reiteration of his early vow to close down the military prison in Guantánamo Bay, where a hundred and sixty-six terror suspects are being held, the vast majority languishing without having faced specific charges or trials, also left some exceedingly tough questions unanswered. Obama said he would lift the moratorium he had imposed on transfers of prisoners to Yemen, because of security in that country. Some fifty-six Yemenis form the core of a group of eighty-six prisoners who have been cleared for release. Once that group is moved out, however, and others are put on trial, there will still be a hard core of suspects whom the government is willing neither to charge nor release. Obama touched on this group glancingly, saying,

Even after we take these steps, one issue will remain: how to deal with those Guantánamo detainees who we know have participated in dangerous plots or attacks, but who cannot be prosecuted—for example because the evidence against them has been compromised or is inadmissible in a court of law. But once we commit to a process of closing Guantánamo, I am confident that this legacy problem can be resolved, consistent with our commitment to the rule of law.

What kind of solution for indefinite detention can be arrived at, however, Obama left for later. It won’t be easy. As Joseph Margulies, clinical professor at Northwestern University Law School and lead counsel in the first Guantánamo case in the Supreme Court, noted, “The devil is in the details.”

Obama’s speech has, at least, put the right questions on the table. Even Margulies, who has been critical of Obama for not doing more to close Guantánamo in the past, admitted he was “excited” by the speech. He said, “All the high-flying rhetoric about values and ‘who we are,’ and national identity is great.” But, he said, “Unless he follows up on it, it’ll all be for naught.” Much of the burden of moving forward, however, is not in Obama’s hands. Within minutes of his speech, conservatives on Capitol Hill had already begun jumping on him for having a “pre-9/11 mindset”—as if, somehow, the 9/11 mindset should last forever.

Photograph by Win McNamee/Getty.