Tahawwur Rana was on trial in Chicago on charges of supporting terrorism, but it was his best friend, David Headley, who grabbed the attention of the international media and, no doubt, the U.S. State Department.

Headley took the witness stand and blew the whistle on Pakistan’s covert support for terrorism. Headley is a U.S. citizen but, more importantly, an ethnic Pakistani super-patriot. He despises India and, like most Pakistanis, he passionately believes the disputed Kashmir region belongs to entirely to his native country.

Tahawwur Rana, seen in this May courtroom sketch, did not testify in his trial on charges of providing material support for terrorism in connection with the Mumbai massacre and another unexecuted plot against a Danish newspaper. Tom Gianni/Associated Press

At Rana’s trial, Headley admitted he was a member of the violent Pakistani extremist group Lashkar-e-Taiba. Posing as a representative of Rana’s First World Immigration consulting company, Headley travelled to Mumbai five times between 2006 and 2008 to scout out targets for Lashkar’s Mumbai attackers.

Following the attacks he used the same cover story in Copenhagen. There, at the behest of alleged al-Qaeda operations chief Ilyas Kashmiri, he did surveillance on the Jylands-Posten newspaper. JP is the newspaper that once published controversial cartoons of the Prophet Muhammad.

Testifies against friend

Headley is a bona fide insider in the tightly knit world of Islamist terrorism and therefore of enormous interest to U.S. intelligence. To avoid the death penalty, he cut a deal with U.S. federal prosecutors. He would testify against his friend Rana in exchange for telling the FBI everything he knew about the fractious world of terrorism in Pakistan.

In dramatic testimony, Headley confirmed what the Indian government has long alleged and the government of Pakistan has long denied: the Lashkar attackers were trained, equipped and bank-rolled by Pakistan’s military intelligence agency — the Directorate of Inter-Services Intelligence, or ISI — and, by extension, the Pakistani government.

Coming on the heels of the recent discovery that Osama Bin Laden for years hid in plain sight just a few kilometres from Pakistan’s elite military academy, Headley’s testimony has implications for Washington’s shaky foreign policy relationship with its erstwhile South Asian ally.

The CIA has been concerned for years that Pakistan is playing a double game – claiming to fight Islamist terrorist organizations in order to obtain billions in U.S. aid, while at the same time supporting and providing a safe haven for the Taliban and al-Qaeda.

The Institute for Conflict Management, a New Delhi-based think-tank that keeps a daily record of terrorist incidents in South Asia, alleges that at present there are 43 active terrorist groups. Some, such as Lashkar, receive support from the Pakistani military and members of the country’s wealthy Islamist anti-American elite, and some do not.

5 kinds of terrorist groups in South Asia

A study done recently by a U.S. government think-tank exclusively for members of Congress and obtained by CBC News sorts the groups into five categories.

Globally oriented groups such as al-Qaeda, Afghanistan-oriented militants such as the Quetta-Shura, led by the Taliban’s Mullah Omar, India- and Kashmir-oriented groups, such as Lashkar-e-Taiba, violent sectarian militants such as the anti-Shia Sipah-e-Shabah, and domestically oriented militants that have turned on the Pakistani government.

Islamist extremism in Pakistan is a front-burner U.S. policy concern in Washington these days. Since Sept. 11 attacks, the U.S. has given Pakistan $20 billion in military and foreign aid. The quid pro quo was supposed to be that Pakistan would fight terrorism.

Headley’s testimony that the Pakistani military intelligence was behind the Mumbai attacks buttressed criticism from members of the U.S. Congress that Pakistan is playing a double game Pakistan’s under-the-table support for terrorist groups hinders the effort by the U.S. and NATO to defeat al-Qaeda and stabilize Afghanistan.

It also underlines a concern voiced by Canadian and American intelligence experts that young radicalized Muslim men from the West are trickling into remote militant training camps in Pakistan’s frontier provinces to learn terrorist tradecraft and will someday return to put their terrorist training to use at home. There are already examples.

Faisal Shahzad, a naturalized U.S. citizen of Pakistani origin who, in May 2010, attempted to set off a crudely constructed car bomb in New York’s Times Square.

The Pakistan Taliban claimed responsibility. And when the leaders of the Toronto 18 were looking to get terrorism training, Lashkar-e-Taiba was the group they contacted.

Troubled relationship underscored

The congressional study says the recent revelation that al-Qaeda founder Osama bin Laden enjoyed apparently several years of relatively comfortable refuge inside Pakistan has led to intensive U.S. government scrutiny of its deeply troubled bilateral relationship with Pakistan.

Congressmen on both sides of the House, according to the congressional study paper, are questioning the wisdom of existing U.S. foreign assistance programs being given to a nation that may not have the intention and/or capacity to be an effective U.S. partner.

Even so, the study also concludes the U.S. cannot afford to throw its apparently double-dealing ally under the bus. If it did, China, or perhaps Iran, might be happy to step in and be Pakistan’s new best friend.

In addition, an important goal of U.S. foreign policy in the post-9/11 period is the creation of a more stable, democratic, and prosperous Pakistan that would combat religious militancy and help prevent another 9/11 style attack on the U.S. Since Pakistan is the epicentre of Islamist anti-Amerian militancy, the U.S. will have to stay engaged in Pakistan no matter how much it suspects its erstwhile ally is playing a double game.

Bill Gillespie is an award-winning CBC journalist who covered the trial of Tahawwur Rana in Chicago.