As Americans reeled after the 9/11 attacks 20 years ago, one question was at the front of many minds: Could even worse be coming? If the terrorists who attacked on September 11 had a crude nuclear bomb on the plane, it wouldn’t have been just the twin towers—the whole lower half of Manhattan could have been turned to rubble and ash, with hundreds of thousands dead and injured. Unfortunately, that possibility was all too real. Investigations after the attacks uncovered focused al Qaeda efforts to get nuclear, biological, and chemical weapons. The nuclear program reported directly to Ayman al-Zawahiri, now the leader of the group, and got as far as carrying out crude but sensible conventional explosive tests for the bomb program in the Afghan desert. Weeks before 9/11, Osama bin Laden and Zawahiri met with two senior Pakistani nuclear scientists and discussed how al Qaeda could get nuclear weapons.
Bulletin of Atomic Scientists 16th Sept 2021 read more »