Early on the morning of Nov. 25, the Obama administration significantly shifted its public position in the then-ongoing standoff between Egypt’s ruling military and pro-democracy demonstrators in Cairo’s Tahrir square. Dropping its weak appeals for “restraint on all sides,” the White House “condemned the excessive use of force” against the protesters and sided with their main demand by asserting that “the full transfer of power to a civilian government must take place . . . as soon as possible.”

The generals got the message and reacted furiously. But most other Egyptians were oblivious — including the young revolutionaries and civilian political elite the administration was trying to support. When I spoke to a range of politicians and demonstrators in Cairo several days later, most were still fuming over the wishy-washy words of press secretary Jay Carney on Nov. 21. Maybe that’s because Carney’s comments were televised — while the subsequent statement was issued off camera, in the name of “the press secretary,” at 3 a.m. Washington time.

The story of that statement is a good example of how President Obama continues to lag on what his own top advisers have called the greatest foreign policy challenge of his administration. A president who began his presidency with a much-promoted public address to the Muslim world from Cairo has rarely found his voice since Egypt and other Arab states tumbled into a new era in which public opinion — the proverbial “Arab street” — matters more than ever.

In the past half-year Obama has given two big set-piece speeches about the events in the Middle East, at the State Department and the United Nations. In both cases he made headlines for what he said about the frozen Israeli-Palestinian conflict, rather than the revolutionary change underway in Arab states. Outside those addresses the president has rarely spoken about the roller-coaster of change underway in Egypt, or the violent repression in Bahrain, or the pivotal civil conflict in Syria. Months of presidential silence go by, while the press shops at State and the White House issue perfunctory statements.

It’s hard to escape the conclusion that Obama simply isn’t much engaged by the fight for freedom in the Middle East or sees it as a distraction from his own priorities. After all, he continues to speak frequently and often provocatively about the causes of Palestinian statehood and nuclear nonproliferation, which he brought with him to office. He recently launched a much-promoted “pivot” of his foreign policy to Asia — a critically important area for the United States but one where no crisis, much less an epochal upheaval, is underway.

Why does this matter? Because for the first time in a generation, the United States needs to reforge its strategic relations with countries such as Egypt — and it can no longer do it by writing checks or supplying tanks. Over the next couple of years the 80 million people of Egypt, and their elected representatives, will need to be convinced that an alliance with the United States is worth preserving.

So far the trend is not good. According to the 2011 Arab Opinion poll, conducted by Shibley Telhami of the University of Maryland with Zogby International, the share of Arabs saying they have a positive view of Obama stands at 34 percent, compared with 39 percent in 2009. The president’s ratings have increased since the Arab Spring began, but when people were asked which countries have “played the most constructive role,” Turkey and France finished first; the United States barely edged out China for third.

Administration officials often argue that Washington is better off keeping a low public profile on Mideast events. Yet France has clearly benefited from Nicolas Sarkozy’s aggressive public support for the revolutions. And the reality is that a large number of Arabs either don’t know what U.S. policy is or misunderstand it. Most Egyptians I talked to during a recent visit to Cairo — including sophisticated political players — believed that Obama’s priorities are to support the Egyptian military and Israel, regardless of what they do.

There are, of course, ways for the United States to demonstrate its continuing value to Egypt and its neighbors that may be more important than public statements. Help for economies devasted by revolution could be crucial in the next couple of years. Security cooperation in places such as the Sinai Peninsula, where al-Qaeda may be seeking a foothold, may also pay off.

But Arabs also need to hear and see that American leaders support their democratic aspirations. The administration is slowly moving in that direction: Secretary of State Hillary Rodham Clinton, for example, has recently prodded both Egypt’s Islamists and the military about sticking to democratic principles. The message, however, needs to be more consistent. And more often than it has, it needs to come from the president.