Looking elsewhere, experts cite some familiar threats and other new ones. An emerging concern: the Islamic Jihad Union, an offshoot of Al Qaeda that operates in the same semiautonomous tribal regions of northwest Pakistan. It allegedly directed a group of German converts and Turks, three of whom were arrested last year on suspicion of plotting to bomb U.S. military targets in Germany. Last month, German police asked for the public's help in tracking down another Islamic Jihad Union-trained convert who is considered dangerous and has posted videos on Turkish websites.
"It is a splinter organization trying to make its mark," Sageman said. "The only way to do that, to make their mark, is to do an attack. There is an internal rivalry among terror groups. The IJU wants to claim to be the new Al Qaeda."
Other hot spots include Yemen, the Sahel region of northern Africa, and war-torn Somalia, where an increasing number of foreign radicals go to train, officials said. Activity also has picked up in Bosnia-Herzegovina and Macedonia as the Balkans become a refuge for foreign militants who fought in Iraq, the Italian anti-terrorism official said.
Agencies have become adept at detecting plots in the making. But the new administration will inherit a persistent nightmare: self-radicalized cells that form with minimal links to established networks and strike without warning.
The Muslim doctors on trial for attempted bombings in London and Glasgow, Scotland, in 2007 illustrate such a scenario. Sageman says autonomous, Internet-driven groups are the threat of the future.
In the larger war of ideas, some experts say, Obama's election serves as ammunition against extremist propaganda.
"If the fact that the grandson of a Kenyan goatherd becomes president of the United States does not undermine the jihadi message that the United States is unjust and oppressive, I don't know what will," Sageman said.
Caprioli, for his part, says Islamic fundamentalists may see the president-elect, a Christian, as an apostate because he did not adopt his African family's Muslim faith.
"They will judge him on his policies, not on his identity," Caprioli said.