Iran’s growing nuclear weapons capability is often condemned, most recently in a December
28th joint statement by the United States and its close European allies. The occasion was the
Iranian action to expand its output of 60 percent enriched uranium. This level of enrichment is
a hair’s breadth from 90 percent enriched or weapon-grade uranium, the enrichment level
most desired for making nuclear weapons. That is also the enrichment level used in Iran’s
nuclear weapons designs, which it nearly perfected during its crash nuclear weapons program
in the early 2000s, codenamed the Amad Plan. This program was shut down in 2003 and
replaced with a smaller, more dispersed nuclear weapons effort, with the decision to make
them postponed.

The unfortunate reality is that Iran already knows how to build nuclear weapons, although
there are some unfinished tasks related to the actual construction of them. If the regime’s
leadership decided to build them, how would it proceed? How long would it take?

The long pole in the tent of building nuclear weapons is essentially complete. Iran can quickly
make enough weapon-grade uranium for many nuclear weapons, something it could not do in 2003. Today, it would need only about a week to produce enough for its first nuclear weapon.
It could have enough weapon-grade uranium for six weapons in one month, and after five
months of producing weapon-grade uranium, it could have enough for twelve.

The other major poles in the tent are “nuclear weaponization” and delivery. Iran has a variety
of delivery systems, including nuclear-capable missiles: the delivery pole is ready.

Weaponization is the pole that needs more work. It involves theoretical calculations and
simulations; development, testing, and construction of the other components of the nuclear
weapon; the conversion of weapon-grade uranium into metallic components; the integration of

all the components into a nuclear weapon; and the preparation for mounting the weapons on
aircraft or missiles or for use in a full-scale underground test. This pole includes the mastery of
the high explosive triggering system, the molding and machining of high explosives, and the
building of a neutron initiator that starts the chain reaction at just the right moment to create a
nuclear explosion.