By FOUAD AJAMI

The sight of Hillary Clinton cutting a rug on the dance floor this week in South Africa gives away the moral obtuseness of America’s chief diplomat. That image will tell the people of the besieged Syrian city of Aleppo, under attack by a merciless regime, all they need to know about the heartlessness of U.S. foreign policy.

True authority over foreign affairs has been vested in the White House, and for that matter, in the Obama campaign apparatus. All the great decisions on foreign policy—Iraq and Afghanistan, the struggle raging in Syria, the challenge posed by the Iranian regime—have been subjugated to the needs of the campaign. All that is left for Mrs. Clinton is the pomp and ceremony and hectic travel schedule.

Much has been made of her time in the air. She is now officially the most traveled secretary of state in American history. She has logged, by one recent count, 843,458 miles and visited 102 countries. (This was before her recent African swing; doubtless her handlers will revise the figures.) In one dispatch, it was breakfast in Vietnam, lunch in Laos, dinner in Cambodia. Officially, she’s always the life of the party.

This is foreign policy trivialized. If Harry Truman’s secretary of state, Dean Acheson, was “present at the creation” of the post-World War II order of states, historians who bother with Mrs. Clinton will judge her as marking time, a witness to the erosion of U.S. authority in the international order.

After settling into her post in early 2009, she made it clear that the “freedom agenda” of the prior administration would be sacrificed. “Ideology is so yesterday,” she bluntly proclaimed in April of that year. This is what her boss had intended all along. The herald of change in international affairs, the man who had hooked crowds in Paris and Berlin and Cairo, was, at heart, a trimmer, timid about America’s possibilities beyond its shores.

AFP/Getty ImagesSecretary of State Hillary Clinton (right) dances with South African Foreign Minister Maite Nkoana-Mashabane in Pretoria, Aug. 7.

Presidents and secretaries of state working in tandem can bend historical outcomes. Think of Truman and Acheson accepting the call of history when the British could no longer assume their imperial role. Likewise, Ronald Reagan and George Shultz pushed Soviet communism into its grave and gave the American people confidence after the diplomatic setbacks of the 1970s and the humiliations handed to U.S. power under the presidency of Jimmy Carter.

Grant Barack Obama and Hillary Clinton their due—they have worked well together, presided over the retrenchment of American power, made a bet that the American people would not notice, or care about, the decline of U.S. authority abroad. This is no small feat.

Yet the passivity of this secretary of state is unprecedented. Mrs. Clinton left no mark on the decision to liquidate the American presence in Iraq—the president’s principal adviser on Iraq was Vice President Joe Biden. We have heard little from her on Afghanistan, except last month to designate it a “major non-NATO ally.” She opened the tumult of the Arab Spring with a monumental misreading of Egypt: Hosni Mubarak was a “friend of my family,” she said, and his reign was stable. She will long be associated with the political abdication and sophistry that has marked this administration’s approach to the Syrian rebellion.

Columnist Bret Stephens on why the Obama administration won’t intervene militarily in Syria until after the election and what the U.S.’s lack of engagement could mean for a post-Assad Syria. Photos: Associated Press

With nothing save her words invested in Syria, she never tires of invoking the specter of jihadists finding their way into the fight: “Those who are attempting to exploit the situation by sending in terrorist fighters must realize they will not be tolerated, first and foremost by the Syrian people.”

Aleppo, an ancient, prosperous city, the country’s economic trading capital, shelled as though it is a foreign city, is subjected to barbarous treatment, and Mrs. Clinton has this to say: “We have to set very clear expectations about avoiding sectarian warfare.”

Syria has now descended, as it was bound to, into a drawn-out conflict, into a full-scale sectarian civil war between the Sunni majority and the Alawi holders of power. But Mrs. Clinton could offer nothing better than this trite, hackneyed observation: “We must figure out ways to hasten the day when bloodshed ends and the political transition begins. We have to make sure that state institutions stay intact.”

These are the words of someone running out the clock on the Syrians, playing for time on behalf of a president who gave her this post knowing there would be at Foggy Bottom a politician like himself instead of a diplomat given to a belief in American power and the American burden in the world.

One doesn’t have to be unduly cynical to read the mind of the secretary of state and that of her closest political strategist, her spouse Bill Clinton. Defeated by Mr. Obama in 2008, the Clintons made the best of it. They rode with him without giving up on the dream of restoration. The passivity of Secretary Clinton, and the role assigned Bill Clinton in the Democratic convention as the one figure who might assure the centrists and independents that Barack Obama is within the political mainstream, are an investment in the future. The morning after the presidential election, the Clintons will be ready. They will wait out an Obama victory and begin to chip away at his authority.

And in the event of an Obama defeat, they will ride to the rescue of a traumatized party. Mrs. Clinton will claim that she has rounded out her résumé. She needn’t repeat fanciful tales of landing in Bosnia under fire in 1996; she will have a record of all those miles she has flown. She will pass in silence over the early hopes she had invested in Syria’s Bashar al-Assad as a reformer, and over the slaughter he unleashed on his people. Her devotees will claim that all was well at State and that Hillary mastered her brief with what she likes to call “people-to-people” diplomacy.

Mr. Ajami is a senior fellow at Stanford University’s Hoover Institution and the author most recently of “The Syrian Rebellion,” just out by Hoover Press.