26/11: Initial LeT plan was to attack Nasscom's Mumbai conference

Initial plans called for one or two fidayeen to storm an annual software conference held there and then to flee the country, writes Stephen Tankel, a visiting scholar at the Carnegie Endowment for International Peace, a think tank.

"The surging jihad in Afghanistan, and eruption of violence in the tribal areas led to fierce ideological debates among militant outfits regarding where to focus their violence," he writes citing David Headley, the Pakistani-American operative who conducted surveillance for the 2008 attacks.

Headley described how the aggression and commitment of those fighting in Afghanistan influenced some fighters to leave Kashmir-centric groups like LeT, which he believed contributed to LeT's decision to "consider a spectacular terrorist strike in India", Tankel writes.

"Who initially floated the idea of upping the ante is uncertain, but between early 2008 and the summer of that year the planned one- or two-person operation expanded into a 10-person assault against multiple targets," he wrote.

Several of those targets were added as late as the summer - a month before the attacks were originally scheduled to occur, writes Tankel, who is also author of the forthcoming book "Storming the World Stage: The Story of Lashkar-e-Taiba".

One of them was the Chabad House, chosen because of the credibility that would come from killing Israeli and American Jews, the most common visitors.

According to Headley, every major LeT operative had an Inter-Services Intelligence (ISI) handler and all of the group's major operations were conducted in coordination with these officers, Tankel notes.

His handler was allegedly one Maj. Iqbal, who Headley said provided approximately $25,000 for surveillance trips to India and, Headley believes, additional funding for a boat that sank during an aborted attempt to strike Mumbai in September 2008.

"If Headley is to be believed and every major LeT member had an ISI handler, then it is reasonable to assume others in the ISI were also aware of the operational details given that a number of the group's senior leaders were involved in planning the attacks," Tankel concludes.