How safe is Pakistan's nuclear weapons arsenal?

Could there be a repetition, I asked, of the August 2001 meeting in Afghanistan at which two retired Pakistani nuclear scientists offered to help Osama bin Laden? "Today, that would not happen," the security official told me.

The professional qualifications of the top security official were impressive. The system he described was complex and substantial. Counterintelligence on weapons security now comes directly to the top security official, not routed via other intelligence agencies, some of which have had past connections with jihadis.

OK, I said, let's suppose the Pakistani security system works. But in a time of political uncertainty, could someone with Islamist sympathies take over the entire system? "The Taliban or al-Qaida are in no position to take over the central government and thereby the National Command Authority," came back the swift answer. This is probably true.

The problem is that Pakistan is entering uncharted political waters. Under President Pervez Musharraf, the military has been ambivalent about taking on Pakistani militants and has become demoralized by losses sustained in jihadi attacks. No political leader except Ms. Bhutto has spelled out clearly that this is now Pakistan's war, not a proxy war for American interests.

The greatest fear of U.S. experts on Pakistan's nuclear security is that disgruntled insiders could penetrate the security system. I want to believe that the Pakistani security system can weed out bad actors before they get their hands on fissile material. But can we be sure?

Trudy Rubin is a columnist for The Philadelphia Inquirer. Her column appears Tuesdays in The Sun. Her e-mail is [e-mail].