It should come as no surprise the United States is holding back $800 million of aid to Pakistan. We've been down this road before. And it's good we're on that road again.

I was in Pakistan days after the 9/11 attacks on the World Trade Center as a journalist. Camped out in Islamabad with the other shaken members of the fourth estate, we were unsure what Pakistan's President Pervez Musharraf would do.

Would he continue supporting the Taliban, and thus aid in the protection of Al Qaeda, risking war with the United States?

Or would Pakistan's president support the United States? That move carried the risk of Musharraf being deposed by militants or a revolution. But being a U.S. ally promised a big reward, too -- restoration of billions of dollars in military aid Congress had stopped sending in the 1990s, when Pakistan went rogue, developing nuclear bombs against Washington's wishes.

Pakistan's president chose the United States. He weathered the subsequent anti-U.S. protests. Predictably, U.S. aid money began pouring in. His country became a forward operating base in America's hunt for Osama bin Laden.

While the cooperation between the two countries did deepen on the surface after the 9/11 terror attacks, those who knew Pakistan understood the relationship was still defined by suspicion on Washington's part on two counts: Pakistan's connections to Islamic extremists and the Taliban, as well as doubts over the security of Pakistan's nuclear arsenal.

The latter point remains a global security issue. Pakistan has been linked to the proliferation of nuclear weapons and missile technology, particularly to North Korea. The U.S. has also spent heavily [with little results] to help the Pakistani military try and achieve "command and control" of its nuclear arsenal, to ensure those nukes don't fall into the hands of terrorists wanting to destroy an infidel city.

When the hunt for Osama bin Laden was in full swing, many of these troubling questions were downplayed in public. The United States needed the deepest level of support it could muster from Pakistan and support its strongman, President Musharraf.

But now that Osama bin Laden has been killed by a team of U.S. Special Forces -- in a hideout on Pakistani soil, near a military academy no less -- the United States is free to once again press hard for answers to these lingering doubts about Pakistan.

First, to what degree are Pakistan's institutions -- its military, government, secret service and religious establishments -- influenced or infiltrated by Islamic extremists?

Second, what are the systems in place to secure Pakistan's nuclear arsenal and, should the government or military fall into the hands of extremists, what measures are in place to keep those nukes from being obtained by people who believe in mass terror?

This isn't fiction from the TV show 24. These are questions under active consideration. U.S. officials and legislators were warned last May that Pakistan might be using some of its U.S. aid to add to its 80 to 100 nuclear devices. Meanwhile, the security of those systems, and the stability of the Pakistani military and its security services, remains unclear.

Bruce Riedel, of the Brookings Institution and co-author of President Obama's Afghanistan-Pakistan strategy review, put the issue into stark relief. He told the New York Times that Pakistan "has more terrorists per square mile than anyplace else on earth, and it has a nuclear weapons program that is growing faster than anyplace else on earth."

If you think this all does sound like it could be lifted from an unused episode of 24, you're right. But Jack Bauer is gone, the show cancelled. This is a real-life episode left for us to deal with.

The world needs a stable Pakistan, if it can get it. So do ordinary Pakistanis, the majority of who want a democracy or, at a minimum, a nation that works. To reach that goal, all countries -- including Canada -- need to ensure aid money goes to the right people.

Follow Miro Cernetig on Twitter: www.twitter.com/miroc