After four exhausting years, Hillary Clinton leaves the State Department with an impressive record of air miles logged, town-hall meetings held, important but neglected issues highlighted, international crises defused, gaffes avoided, citizens of the United States and the world wowed, and White House policies capably carried out. When Clinton and President Obama recently sat down for an interview on “60 Minutes,” they all but held hands, swearing deathless affection and respect, and they seemed to mean it. But Clinton was denied the chance to be a truly great Secretary of State—another George C. Marshall or Dean Acheson—by both history and the President she served.

Last year, Denis McDonough, a top White House adviser, described Clinton’s role as “the principal implementer” of Obama’s foreign policy. On a few occasions, her advice helped to tip the scales—the 2009 surge in Afghanistan, which she strongly supported, was one—but she and her department were never trusted with the policy blueprints. From Iran and Israel to nonproliferation and human rights, the President has kept policymaking inside the White House, tightly held by a small circle of political advisers.

This shouldn’t matter, except maybe to Washington insiders, as long as the policies were the right ones. By the standard of the Hippocratic oath, they have been. Judging from last fall’s campaign, the biggest preventable foreign-policy disaster of Barack Obama’s first term was the killing in Benghazi of the U.S. Ambassador to Libya and three other Americans. Benghazi was a tragedy for which the State Department bore much responsibility; but, after the Bush years, the rest of the Administration’s record is no minor achievement. Obama and Clinton inherited two unwinnable wars, a toxic international atmosphere in which America was reviled where it wasn’t ignored, and a badly diminished stock of national power.

The criticism that there is no encompassing “Obama doctrine” misses the point. Geopolitics today is too complex, messy, and various to be bent to America’s will by an overarching doctrine like containment, or a massive initiative like the Marshall Plan, or a single breakthrough like Nixon’s trip to China. A doctrine was what put the country in a deep hole; climbing out required restraint, flexibility, and opportunism. A first-term Secretary of State with one grand strategic vision wouldn’t have matched the demands of the moment, which called for a fox, not a hedgehog. Clinton’s true legacy might be the countless public events that she held from Lahore to Kinshasa, where thousands of ordinary people got to question the U.S. Secretary of State, and where the topic was often something like women’s rights or access to clean water. These efforts were sometimes derided as soft, and marginal to real foreign policy, but Clinton—who is, after all, a politician—knew that she would have to be seen listening in order to help regain the world’s respect. That and four years of carefully calibrated Presidential rhetoric and support for multilateralism have gone a long way to restoring America’s legitimacy as the leading global actor.

If there is one idea that sums up Obama’s approach to foreign policy, it’s engagement. “We will extend a hand if you are willing to unclench your fist,” he proclaimed in his first Inaugural, and in his second (which barely touched on foreign policy) he said, “We will show the courage to try and resolve our differences with other nations peacefully. Not because we are naïve about the dangers we face, but because engagement can more durably lift suspicion and fear.” But, in his first term, Obama didn’t live up to the promise of engagement. When the world proved recalcitrant, the President was too disengaged to do it himself, and he didn’t give his Secretary of State the chance.

On Afghanistan, the White House pursued a military strategy for more than two years without enabling the Administration’s diplomats to negotiate seriously with the Taliban or work out a regional framework for peace; then Obama announced a deadline for withdrawal, which removed the incentive for America’s enemies in Afghanistan to compromise. On Iran, the State Department has played little role, while the President’s two-track policy of talks and sanctions soon narrowed to one, bringing Iran no closer to abandoning its nuclear ambitions. On Israel and Palestine, there has been practically no diplomacy at all.

The standard debates in American foreign policy—realism vs. idealism, heavy footprint vs. light footprint—don’t get to the heart of the problem with Obama’s foreign policy. It’s not that diplomatic engagement is the wrong approach; it’s just that the President’s first four years have given us the idea of diplomacy more than the thing itself. In a forthcoming book, “The Dispensable Nation: American Foreign Policy in Retreat,” Vali Nasr, a former adviser under Hillary Clinton and the late Richard Holbrooke, argues that, from North Africa to Afghanistan and Pakistan, the White House has relied too much on the military and the C.I.A. (mainly in the form of drones) to guide policy: “These agencies’ solutions were not, and could never be, a substitute for the type of patient, long-range, credible diplomacy that garners the respect of our allies and their support when we need it.” In Nasr’s view, a White House that feared being called soft and wanted to keep intractable foreign entanglements out of the news turned to Clinton only after things had fallen apart, as in Pakistan at the end of 2011, when she moved to repair a relationship that had degenerated into outright antagonism.

Obama and Clinton wanted to “pivot” away from the Middle East, toward the Pacific, but a bloody hand keeps reaching out to pull America back. Sixty thousand people have died in Syria’s civil war, Egypt is on the brink of state collapse, and the region is moving toward Sunni-Shiite confrontation. These are not problems that can be addressed by drone strikes and fitful diplomacy. The President is wise to acknowledge America’s inability to solve them by itself—“We are not going to be able to control every aspect of every transition and transformation,” he said on “60 Minutes”—but a tragic sense of limitation is not a substitute for real, prolonged engagement, which always carries the risk of failure. Whether Obama believes that America can or should shape the outcome, the greater Middle East will remain an American problem, and he will need to give his next Secretary of State, John Kerry, the authority that he denied his last one, to put the country’s prestige on the line by wading deep into the morass. ♦