Both men were later captured by police and details of the plot uncovered after they accidentally set off an explosion in the Manila apartment they were using as a bomb factory. Ramzi was later tried in the U.S. and remains in jail to this day for his role in the 1993 bombing of the World Trade Center, which itself could be seen as a dry run for 9/11.
The parallels between the two attempts underline just how vulnerable airliners remain, says Zachary Abuza, a terror expert who teaches at Simmons College in Boston, Mass. "The amount of explosive you need is really very small," Abuza notes. "It doesn't take much to bring a plane down. And the return is huge. They are targeting the global economy and this remains a huge way to make a dent very quickly by disrupting business and tourism." He and other experts warn that bombs on airplanes will always remain one of the most tempting targets for terrorists, who have killed almost two thousand passengers over the last three decades.
The foiled plot also underlines the fact that, for all the talk in recent years about al-Qaeda focusing on coming up with a new form of terror attack be it with weapons of mass destruction or against a target other than air travel the group tends to stick with what they believe is a good plan, notes Rohan Gunaratna, author of Inside al-Qaeda. "They think in the long term, over decades," Gunaratna says. "They will keep trying the same plan until they get it right, as was the case with the World Trade Center." From "Richard Reid the shoe bomber to the arrest by Philippine police last year of Islamic extremists in Manila who had manufactured explosives they managed to get into toothpaste tubes, the pattern is there," concurs Abuza. "They will keep trying. And we don't know the chemical composition of this latest attempt, but if they have come up with something that is stable and easily disguised we could really have a problem."