Associated Press

WASHINGTON — The interrogations of Sept. 11 mastermind Khalid Shaikh Mohammed portray an al-Qaida terror network that is fluid in its planning, willing to go slowly to achieve spectacular results and determined to carry out plots even when initially thwarted.

Along the way, terrorist volunteers are shifted between different attack plots based on opportunity, according to interrogation reports reviewed by The Associated Press.

For instance, Mohammed told his captors that when two of the four original operatives assigned by Osama bin Laden to the Sept. 11 plot failed to get U.S. visas because they were Yemenis, bin Laden simply changed course and asked the two to study the possibility of hijacking planes in Asia.

Their “mission in East Asia was to … fly commercial airliners to gain familiarity” with how jets operated in that region, Mohammed told questioners in one report.

Bin Laden then came up with additional participants for the Sept. 11 plan, offering a member of his personal security detail as well as a large group of young Saudi men who ultimately made it onto the ill-fated jetliners, Mohammed is quoted in the interrogation reports as saying.

The plan evolved several times over five years — with bin Laden making the final decisions.

“What we learned post-Sept. 11 was that al-Qaida is a very top-down structure, with command and control very closely controlled,” former CIA terrorism expert Vincent Cannistraro said Monday. “Khalid Shaikh Mohammed essentially had to get every ‘i’ dotted and every ‘t’ crossed from bin Laden himself.”

Mohammed divulged to interrogators that he first devised the Sept. 11 plot after three of his cohorts were thwarted in a 1995 plan, codenamed Bojinka, to blow up 12 airliners in southeast Asia.

Mohammed kept the core idea of Bojinka in place, initially proposing to bin Laden in 1996 that al-Qaida operatives hijack 10 planes — five on each American coast. Then he began refining the plan.

At one point, Mohammed said, he considered using a shoe bomb — something British radical Richard Reid tried after Sept. 11. At another point, he said the plan resembled “a smaller version of Bojinka.”

Each adjustment came after Mohammed ran into a roadblock. When bin Laden thought it would be too difficult to pull off simultaneous hijackings in multiple time zones, like two coasts of the United States and Asia, Mohammed scaled back.

“Bin Laden canceled the East Asia portion of the plan in April or May (2000) claiming that it would be too difficult to synchronize,” one interrogation report states.

Along the way, operatives originally assigned to the Sept. 11 plot were redeployed to other terror plans.

For instance, the two Yemenis assigned to the suicide hijackings as early as 1996 were reassigned to attacks in Yemen, where the USS Cole was eventually bombed in 2000.

And four others, who in line for the Sept. 11 attacks, were redeployed for a plan, later foiled, to bomb “U.S. and Jewish targets in Singapore,” the reports state.

Failures seem to be no roadblock to bin Laden. In fact, recycling old terrorist plans is portrayed as a norm in Mohammed’s interrogations.

Though al-Qaida failed to topple the World Trade Center in a 1993 bombing, the towers were still a prime target for the 2001 mission. The 1995 plan for Asian hijackings was just as interesting to al-Qaida four years later.

And an idea the 1995 Bojinka plotters discussed — flying planes into U.S. landmarks — became the centerpiece of its 2001 attack.

“They think in the long term, no doubt,” Cannistraro said of al-Qaida. “They have a long-term target and if they don’t succeed at first, they go back.”

As for the operatives who carry out attacks, no detail is too small. Mohammed discussed with interrogators how Sept. 11 operatives were trained in the very basics of American society — including how to read telephone Yellow Pages and how to access commercial airline timetables.