It is too soon to tell whether President Obama’s 55-minute speech to the Muslim world from Cairo will be the balm to America’s broken relationship with Islam that White House officials hope.

Some early signs are promising — and not just that several times someone in Mr. Obama’s audience in the domed hall yelled out, “I love you!”

Mr. Obama drew applause by promising that America will never be at war with Islam. While maintaining that the United States will continue to fight terrorism and will not shy away from its alliance with Israel, he also invoked the name “Palestine” several times to refer to a Palestinian state. He called publicly for an end to Israeli settlements in the West Bank, and drew parallels between Islam, Christianity and Judaism, embracing all the children of Abraham.

But one thing is already clear. While Mr. Obama’s strong words may resonate today, on the Arab street and in the madrassas and the tea shops and dining tables where the world’s 1.5 billion Muslims congregate, the future actions of Mr. Obama will be far more important.

For all the talk right now about how much President Bush alienated the Muslim world, Bush administration officials, from the president on down, publicly said nice things about America and Islam as well. Remember Mr. Bush’s stirring speech, in the early days after September 11? Speaking before a joint session of Congress on Sept. 20, 2001, Mr. Bush sounded eerily similar to Mr. Obama today.

“I also want to speak tonight directly to Muslims throughout the world,” he said. “We respect your faith. It’s practiced freely by many millions of Americans and by millions more in countries that America counts as friends. Its teachings are good and peaceful. And those who commit evil in the name of Allah blaspheme the name of Allah. The terrorists are traitors to their own faith, trying in effect to hijack Islam itself.”

“The enemy of America is not our many Muslims friends,” Mr. Bush said, to applause. “It is not our many Arab friends. Our enemy is a radical network of terrorists and every government that supports them.”

In the seven more years that he would govern the United States, Mr. Bush would often repeat those words, or ones similar. So too would his advisers. And yet, America’s relationship with Muslims continued to deteriorate.

Ultimately, policies matter more than words, many Muslim scholars say. They point to the wars in Iraq and Afghanistan, the Bush administration’s decision to delay calling for a ceasefire back in the summer of 2006 when Israel was pounding Hezbollah targets in Lebanon, America’s refusal to support a Palestinian national unity government that included the militant Islamist organization, Hamas, despite the fact that the United States had initially pushed for those same elections, expecting Hamas to lose.

For Mr. Obama’s words to mean anything, they say, American policy will have to change. And as gifted an orator as the president is, changing the behemoth of United States foreign policy is no easy task, particularly since America’s interests, in many ways, remain the same no matter who is in the White House.

Mr. Obama, while calling for a withdrawal of troops from Iraq (a plus in the minds of many Muslims) has increased the number of American troops in Afghanistan (a minus for many Muslims). He was noticeably silent during the Israeli siege of Gaza earlier this year, which many Muslims revile as disproportionate. During the Cairo speech on Thursday, he repeated the Bush era ban against official American dealings with Hamas, reiterating that his government won’t engage Hamas until it meets conditions imposed by the Bush administration, the European Union, Russia and the United Nations.

Whether Mr. Obama can find a way to maneuver between America’s entrenched foreign policy and his own bold vision for trying to forge a peace between America and Islam—and Israel and Palestine, for that matter—may well end up becoming the benchmark against which his presidency will be judged in the Muslim world.

“ ‘Show me the money’ is the attitude of the Arab and the Muslim world,” said Ziad Asali, president of the American Task Force on Palestine. But, he added, that Mr. Obama has some credibility at the moment. He pointed to the brewing fight between the Obama administration and Israel on settlements. “This is going to be the litmus test.”