RIYADH, Saudi Arabia - -Just as President Barack Obama arrived in the Middle East yesterday to deliver his long-planned appeal for mutual understanding, the Arab world heard unexpectedly from another voice: Osama bin Laden, accusing the American president via audiotape of sowing new seeds of hatred.
The evident attempt by al-Qaida's leader to undercut Obama's speech to Muslims today served as a reminder of the hurdles confronting the United States in the region and of the magnitude of the task facing the president as he works to "reset" U.S. ties with Muslim countries.
But the lunge for attention suggested that terrorist leaders, who have grappled with recent criticism from former followers and from Muslims disaffected by their brutal tactics, might fear an erosion of support for their extreme positions as Obama's popularity grows in Arab countries.
"This guy sends chills up their spine," said Tom Sanderson, deputy director of the Transnational Threats Program at the Center for Strategic and International Studies, a think tank. "Obama is laying groundwork for relations with Muslim countries. Here's someone who really pulls the carpet out from under them."
Separate audiotapes of words purportedly spoken by bin Laden and his chief deputy, Ayman al-Zawahiri, were aired by the Arab-language satellite television station Al Jazeera as Obama was arriving in Saudi Arabia, a day before his scheduled speech in Cairo.
The White House saw the tapes as a likely attempt by al-Qaida's leaders to undercut Obama's mission and to disrupt the message of conciliation and trust he wants to convey.
"I don't think it's surprising that al-Qaida would want to shift attention away from the president's historic efforts ... to reach out and have an open dialogue with the Muslim world," said Robert Gibbs, Obama's press secretary, as the president was holding private meetings with King Abdullah of Saudi Arabia.
However, U.S. officials said they could not positively verify the tapes' authenticity. They said they were assuming that the speakers actually were bin Laden and al-Zawahiri, and that the militant leaders had intended that their statements coincide with Obama's arrival.
"I don't think the timing is of coincidence," said Philip J. Crowley, a State Department spokesman.
