From Lebanese guerrillas to Saudi preachers, Islamic extremists have warned followers not to be taken in by President Barack Obama's conciliatory words - a sign that some may be nervous about losing support if animosity toward the US fades.
But even moderates warn Obama will have to quickly follow his call for a new relationship with the Islamic world with bold actions to prevent a disappointed backlash.
In his speech in Cairo Thursday, Obama listed confronting "violent extremism" as the top priority in addressing tensions between the US and Muslims. He urged the Islamic world to reject radical ideologies and promised to work aggressively to end the Israeli-Palestinian conflict. He also said the US does not accept the legitimacy of continued Israeli settlement in the West Bank and endorsed a Palestinian state.
There are already some indications his words are having the desired effect of undercutting extremists. A militant leader in Egypt called on the Taliban to respond positively to Obama's gestures, and Hamas militants in Gaza say they are ready "to build on this speech."
Obama may have managed to "plant the seed of doubt in some minds," said Robert Malley, senior analyst at the International Crisis Group think tank. "There was enough ... that represented openings for those who wanted openings."
Yet Obama's eloquent promises were seen as only a small step toward halting the region's drift toward militancy, accelerated in recent years by the US invasions of Iraq and Afghanistan and Washington's perceived pro-Israel bias.
He will be most closely watched on the Israeli-Palestinian conflict, particularly his push to get Israel to comply with a settlement freeze. That is something no US administration before him has accomplished.
"Extremists will only be disarmed when the US takes a more neutral stand on Israel," said Abdel Wahab al-Qasab, a Qatar-based analyst.
Obama has so far followed the Bush administration's policy of not talking directly to Hamas, which the US regards as a terrorist organization. But in his remarks in Cairo, he seemed to suggest some basis for believing that Palestinian militants who rule Gaza might be drawn into the peace process.
Obama's Mideast envoy George Mitchell is coming to the region this week to push the president's agenda with Israelis and Palestinians. He is tentatively scheduled to stop in Syria, where Hamas is headquartered. But a State Department spokesman said Mitchell has no plans to talk to Hamas.
Obama's message also contained an assurance that US troops in Afghanistan fighting al-Qaida and the Taliban won't stay longer than absolutely necessary. That too may have resonated with militants in that region, said Ahmed Rashid, a Lahore-based analyst and author of a book on the Taliban.
"The extremists used to lie that the U.S. wants military bases in this region," he said.
Essam Derbala, a leader of one of Egypt's largest militant groups, al-Gamaa al-Islamiyya Al-Qaida, told an Egyptian newspaper over the weekend that the Taliban should reciprocate by announcing they will no longer target Americans. That would ensure US troops will eventually leave the region, he said.
Still, many extremists remain wary of the US outreach.
Two influential fundamentalist groups, Lebanon's Iranian-backed Hezbollah and Egypt's opposition Muslim Brotherhood, as well as a Saudi preacher, accused Obama of being deceptive. They said he offered soft words to hide unchanged anti-Muslim positions. But that could indicate their nervousness that Obama's strategy could undercut support for militancy.
This week's elections in Lebanon and Iran could give an early indication of sentiments in the region.
In Lebanon, Shiite militant group Hezbollah and its allies tried to unseat a pro-Western coalition in a vote on Sunday. In Iran's June 12 vote, hard-line President Mahmoud Ahmadinejad is facing a pro-reform challenger likely to take a less confrontational approach with the US if elected.
But what many in the Muslim world will be waiting to see is whether Obama delivers on expectations of a tougher US stance toward Israel.
"If the Israelis continue with settlement activity and defiance and President Obama does nothing, the repercussions will be major," said Saeb Erekat, an aide to Western-backed Palestinian President Mahmoud Abbas. "We're at a crossroads."
While seemingly tougher on Israel than his predecessor George W. Bush, Obama has not said what, if any, action would take if Israel defies him on settlements. He also has made clear that he is not dramatically revising the fundamentals of past US policy.
Like Bush, he remains committed to Israel's security, is banking on the unpopular Abbas and refuses to talk to Abbas' rival, Hamas, unless the Islamic militant group recognizes Israel and renounces violence.
Despite disappointment that the US position had not shifted more dramatically, Hamas leaders praised Obama's shift in tone. Hamas is eager to win international acceptance of its rule in Gaza, and has gone out of its way to sound pragmatic.
"We think we can build on this speech," Hamas spokesman Fawzi Barhoum said Saturday. "We can take positive things from the speech to open communications with Obama and the US administration."
In the end, many Muslims were heartened by Obama's speech because they saw it as a significant change in the tone of discourse with Muslims. They noted he did not use the word "terrorism" or "terrorist" once in the 55-minute address - words that many thought had been devalued under the Bush administration and too often equated with Muslims.
They also heard a more respectful US leader who quoted from the Quran, or Islamic holy book, greeted them in Arabic, and removed his shoes when he toured a Cairo mosque.
One militant Web site that often carries statements from al-Qaida had unusual praise for Obama after the speech, noting his quotations from the Quran demonstrated respect for Islam and branding him the "wise enemy."