Analysts suspect Thursday's attack in London was motivated by Britain's role in Iraq.
Investigators still don't know who carried out last Thursday's attacks in London. But they say those responsible were probably Islamist terrorists who viewed their assault as revenge for Britain's part in the Iraq war.
The attacks that killed at least 52 in London follow two years in which the Iraq war has inflamed Islamist hatred of the US and key allies like Britain.
According to US assessments, the turmoil in Iraq has replaced the still-simmering conflict in Afghanistan as the chief recruiter of international jihadis. Analysts say anger over the conflict is helping to spread the ideology of global jihad to young Muslims in Europe.
But it is the confluence of America's decision to invade Iraq and new communication technologies that has created the most powerful machine for recruiting new terrorists in history, says Evan Kohlmann, an American terrorism consultant who has tracked jihadi websites since the late 1990s.
America and its allies are now facing a multifront war: In Iraq, which is turning out a new generation of Arab jihadis; in Europe, where Muslim admirers of Al Qaeda are embracing the cause because of anger over the Iraq war; and on the Internet, which has become a megaphone for radical jihadi ideologies.
Counterterrorism officials often talk about the phenomenon of "terrorist dispersal," which is when radicalized foreigners carry jihad and their guerrilla skills back to their homelands.
But most analysts speculate that those responsible for Thursday's attacks in London were not veterans of the Iraqi insurgency. Instead, the best guess is that they were composed primarily of Muslims living in Europe, inspired by Al Qaeda sympathizers who promise salvation and glory in exchange for violence, much as was the case with the Madrid blasts that killed 190 last year.
"The world is just starting to understand the real influence of the Internet as an open university of jihad,'' says Reuven Paz, the head of the Project for the Research of Islamic Movements in Israel. "Like the attacks in Madrid, the bombings in London should be viewed as an export of the war in Iraq to Europe, based on local adherents of global jihad rather than on volunteers from the heart of the Arab world."