No fewer than a third of the alleged terrorists on the FBI's list of most wanted terrorists are Egyptian, as is one of Osama bin Laden's closest and most influential aides, Ayman al-Zawahri.
The connection between Egypt's home-grown Islamist movements and the transnational al-Qaeda is currently a matter of intense speculation in Cairo. When it was facing its own terrorist violence in the 1990s, the Egyptian government frequently blamed terrorists based in Afghanistan but rarely offered proof, and analysts continue to disagree about the strength of the Egyptian presence in al-Qaeda's ranks.
"The media are trying to make the role of Egypt in all this into more than it is," said Dia Rashwan, one of Egypt's most respected experts on Islamist groups. "This is simply untrue. There's no proof."
Others are not so sure. Apart from the visible presence of Zawahri, there are thought to be a number of other Egyptians in Afghanistan.
"We can measure their number in tens, rather than hundreds, but they are definitely there," insists Muhammed Salah, a journalist for the London-based al-Hayat newspaper, who has close contacts with Egyptian Islamists.
What is clear, however, is that Egyptian political and religious ferment has long had an influence on groups based outside its borders. The Islamist movement's spiritual father is Hassan al-Banna, an Egyptian who founded the Muslim Brotherhood in 1928. The group aimed to establish an Islamic state in Egypt and was responsible for a number of assassinations. By the 1940s it had half a million members.
Although the Brotherhood later renounced violence, a number of splinter groups continued to advocate the use of force. In the meantime, the state attempted to co-opt the moderates and their large popular base, while cracking down hard on the extremists, often radicalising them still more in the process.
In 1980, the movement was strengthened when then President Anwar Sadat called on Egyptians to help Afghans expel Soviet troops. Fuelled by CIA-funded weaponry and their own religious zeal they, like the other so-called "Arab Afghans", later came back to haunt their country, finding sympathy among the politically repressed and economically deprived youth.
In October 1981, they turned their guns on Sadat.
Throughout the 1990s two of the groups involved in Sadat's assassination, Islamic Jihad and al-Gama'a al-Islamiyya, staged attacks in Egypt. Both aimed to replace the government with their version of an Islamic state, but differed in tactics.
Jihad, the smaller of the two, tried to bring about a coup d'Θtat by assassinating government officials.
Al-Gama'a had a broader agenda, trying to spread its own literalist version of Islam among a broad popular base, while at the same time taking action to destabilise the state. With a large following, particularly among the disaffected youth in the south of the country, it pulled off high-profile attacks on tourists and policemen, ending with the November 1997 attack that killed 58 tourists in Luxor.
The brutality of the Luxor massacre, in which some victims had their throats slit, shocked the Egyptian public as much as the rest of the world. Already weakened by pressure from Egypt's security forces, the movement saw its popular base wither overnight. Soon afterwards, its leaders issued a unilateral ceasefire, and in 1999 both it and some Jihad members still in Egypt renounced violence and applied to establish their own political parties.
However, many of Jihad and Gama'a members who had fled Egypt during the 1980s and 1990s were still committed to terrorist tactics. The core of Jihad, including its leader, Ayman Zawahri, went to Afghanistan and was under the protection of Osama bin Laden. In 1998, the year of the attacks on American embassies in East Africa, Zawahri announced an alliance with bin Laden. Other Jihad leaders opposed the move, fearing that this would undermine their power and make them a target of the US.
The same year, Zawahri announced his resignation from Jihad's leadership. But, according to Muhammed Salah, without him Jihad was cut off from the resources of bin Laden and had no funding or base of operations. Zawahri quietly returned to the helm, where he appears to have remained.
"Jihad and al-Qaeda are now one organisation," said Salah.