In order to construct an operational nuclear device, terrorists need to obtain the requisite fissile materials – Highly Enriched Uranium (HEU) or plutonium. It has been proved that, generally, it is much simpler to devise a crude nuclear bomb with HEU than with plutonium. Hence, terrorists can have ‘reasonable confidence’ in the performance of weapons-grade HEU bombs. The magnitude of the threat of nuclear terrorism from Pakistan’s HEU-based nuclear weapons programme is assuming alarming proportions. However, adequate preventive steps can be taken to minimize the danger.