Opening arguments begin Monday in a Chicago trial that could complicate the already-fragile relationship between the U.S. and Pakistan. The case involves a man accused of helping facilitate the 2008 terrorist attacks in Mumbai, India, and the defendant, Pakistani-Canadian Tahawwur Rana, faces life in prison if he is convicted.

But even before opening statements start, the issue of Rana’s guilt or innocence has been eclipsed by what witnesses in the case might reveal on the stand about Pakistan’s links to terrorism. The 10 gunmen who launched coordinated attacks against luxury hotels, cafes, a railway station and other targets in Mumbai were from Pakistan, and a Pakistani terrorist group has taken responsibility for the attacks. The question has always been: How much was Pakistani intelligence also involved?

Indian police intercepted some of the cellphone conversations the attackers were having with their handlers in Pakistan during the actual attack in November 2008. With chilling detachment, one handler told one of the gunmen to go ahead and kill the hostages he had taken. The handler said he would “stay on the phone and listen for the gunshots.” In another captured conversation, the young man was told not to panic. The only way his mission would be successful, he was told, was “if he was killed.” Precisely who was on that phone, and whom he worked for, has been part of the speculation surrounding the attacks. More details could be revealed in the testimony scheduled in the coming days.

Rana is a Chicago businessman who owned an immigration law office called First World Immigration Services. Prosecutors say that Rana allowed someone to use the business as a cover to scout the Mumbai attacks — and that someone was a Pakistani-American named David Coleman Headley. Headley, 50, pleaded guilty last year to terrorism charges and now faces a life sentence. The question in this trial is expected to be about whether Rana knew what Headley was up to and knew about the Mumbai plot in advance. Charles Swift, Rana’s defense attorney, says he didn’t.

“By everyone’s account, whether you are the government or us, this is all a question of degree,” said Swift. “Dr. Rana is either an innocent bystander who had the misfortune of knowing a bad guy or helped a bad guy.”

Prosecutors say Rana falsified immigration documents for Headley and then allowed him to open a branch of the law office in Mumbai so he would have a cover story for being there as he did reconnaissance for the attacks. The keen interest in the trial is what other details, not just about Rana, Headley will provide when he takes the stand.

What has been odd about the trial — as lawyers picked jurors last week and swore them in — is that outside the courtroom the primary focus hasn’t been on Rana at all. Instead, the main attraction has been on how big Pakistan’s role in the attacks actually was. Headley has links to Pakistan’s intelligence agency, known as the ISI. When he testifies against Rana, Swift says, he is going to provide publicly, for the first time, details about the run-up to the attack on India.

“This case is really the only case that’s going to look deeply into the Mumbai conspiracy, into U.S. operations, our own operations there and ISI’s operations in sponsoring some of these terrorist groups,” said Swift.

Rana’s trial couldn’t come at a more politically charged time — just weeks after the killing of Osama bin Laden in Pakistan. The fact that bin Laden could have been hiding in Abbottabad, Pakistan, a garrison town less than an hour from the Pakistani capital, for five years has raised questions about just how much Pakistan’s military and intelligence services knew about the al-Qaida leader’s whereabouts.

“It is a big deal because it is part of an evolving revelation of things we already knew,” said Christine Fair, a professor and terrorism expert at Georgetown University. “For those, in the wake of bin Laden, who are out for blood, this is another opportunity to bludgeon Pakistan for its various, numerous shortcomings in the war on terror.”

In a trial that is expected to last for weeks, the job for defense attorneys is to try to get the focus back on their client, and what he actually did or didn’t do ahead of the Mumbai attacks. Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.