The AQ Khan network had advanced nuclear-weapons designs that could fit on ballistic missiles, the Washington Post reported yesterday. The intelligence community has an analysis that determined that Iran, North Korea, and other clients of Khan could have everything they need besides fissile material to build nuclear warheads, a much graver situation than originally thought when the Khan network got exposed. In fact, Khan’s clients may not just have included nations:

An international smuggling ring that sold bomb-related parts to Libya, Iran and North Korea also managed to acquire blueprints for an advanced nuclear weapon, according to a draft report by a former top U.N. arms inspector that suggests the plans could have been shared secretly with any number of countries or rogue groups.

The drawings, discovered in 2006 on computers owned by Swiss businessmen, included essential details for building a compact nuclear device that could be fitted on a type of ballistic missile used by Iran and more than a dozen developing countries, the report states.

The computer contents — among more than 1,000 gigabytes of data seized — were recently destroyed by Swiss authorities under the supervision of the U.N. nuclear watchdog agency, which is investigating the now-defunct smuggling ring previously led by Pakistani scientist Abdul Qadeer Khan.

But U.N. officials cannot rule out the possibility that the blueprints were shared with others before their discovery, said the report’s author, David Albright, a prominent nuclear weapons expert who spent four years researching the smuggling network.

Earlier analyses of the AQ Khan product suggested that the types of device designs it produced would have little practical value as end products themselves. The devices were too heavy and too awkward for ballistic missiles or for terrorist sneak attacks. However, the Swiss discovery shows that Khan also had more compact and efficient design available — and now no one knows how many copies got into how many hands.

The Pakistanis officially forgave Khan a few years ago, but they have now found out that his sins went beyond what they imagined. According to the report, the Musharraf government confirmed that the designs represented their most classified work and modern weapons in their arsenal. They realized that Khan sold out their most critical work to foreigners for profit and left them exposed to hostile powers, and apparently they still felt some surprise about it. They had claimed that Khan never stole Pakistan’s own designs.

This makes it even more critical to keep uranium enrichment out of the hands of nations with ballistic missile capability as well as terrorist connections. Iran qualifies on both counts. If they acquired the plans discovered on the computer of Khan’s Swiss colleagues, the only part they don’t have is the weapons-grade uranium or plutonium.