“When Barack Obama was elected, they had enough fissile material, nuclear material, to make one bomb. Now they have enough to make five.  They’re racing toward a nuclear weapon.” – Republican Vice Presidential Nominee Paul Ryan, October 11, 2012.

Fact: Iran does not have any fissile nuclear material that could be used in a nuclear weapon. Iran has low and medium-enriched uranium, but does not possess weapons-grade uranium, which would be required to build a nuclear weapon.  Iran’s uranium stockpiles are also not suitable for a “dirty bomb,” according to the Federation of American Scientists.

Congressman Ryan’s figure of five nuclear weapons comes from a May 25 report by the Institute for Science and International Security (ISIS).  As ISIS explains, to obtain the fuel for a nuclear weapon, Iran would have to further enrich its existing low and medium-enriched uranium to weapons grade (90%).  However, Iran’s enrichment sites and uranium stockpile are under the supervision of the International Atomic Energy Agency (IAEA), and ISIS reports that any such effort by Iran currently “could not escape detection by the IAEA or the United States.”

Since that time, Iran has converted 71.25 kg of 19.75% enriched uranium into a form that cannot be further enriched, decreasing its usable stockpiles. According to the latest IAEA report, Iran’s existing stockpile consists of 5,309 kg of uranium enriched to 3.5% and 116.5 kg of uranium enriched to 19.75%.

Acquiring weapons-grade fuel is only one of the steps necessary to develop a nuclear weapon – something the U.S. and Israeli intelligence communities agree that Iran has not decided to do.  If Iran were to make the decision to develop a nuclear weapon, U.S. intelligence assesses that it would take Iran at least two to three years to develop a deliverable nuclear weapon.

Secretary of Defense Leon Panetta has explained that, were Iran to decide to construct a nuclear weapon, it would take Iran up to three years to actually build one given current capabilities:

  • Panetta: “The consensus is that, if they decided to do it, it would probably take them about a year to be able to produce a bomb and then possibly another one to two years in order to put it on a deliverable vehicle of some sort in order to deliver that weapon” (60 Minutes; June 10, 2012)

Director of National Intelligence James Clapper indicated that it would take even longer when testifying before Congress.  Asked by Senate Armed Services Chairman Carl Levin about whether he disagreed with Panetta’s timeline, he said:

It is also critical to note that these timelines don’t begin until Iran has made the decision to build a nuclear weapon.

The path to a producing a nuclear weapon would involve several steps for Iran that have not been taken:

  1. A decision to make a bomb—Iran has not decided to actively build a bomb according to U.S. intelligence
  2. Sufficient quantities of Highly Enriched Uranium (HEU)– Iran has not enriched uranium to weapons grade–90%.  It has enriched uranium to lower levels – 5% and 20%. Any move to enrich uranium above 20% would be detected by inspectors from the International Atomic Energy Agency.
  3. A device – a crude nuclear device would take a year for Iran to build, but this would be a heavy device deliverable by a truck but not Iran’s planes or missiles.
  4. Miniaturizing a warhead – producing a sophisticated nuclear warhead that could be deliverable by missile would take Iran at “another two to three, potentially out to five years,” according to Congressional testimony by General James Cartwright, the then-Vice Chairman of the Joint Chiefs of Staff.
  5. A delivery vehicle – Iran would need to fit the warhead on a ballistic missile and the warhead would have to be sturdy enough to handle re-entry into the atmosphere.  Iran has not demonstrated the capability to build such a vehicle.

(5 steps adapted from “Foreign Policy: How Iran Can Build a Bomb; Cirincioni, Connor July 1, 2010”):

Any move towards building a nuclear bomb would be likely detected by the international community:

  • Secretary of Defense Leon Panetta recently said that if the U.S. detects Iran is moving to develop nuclear weapons, it will have “a little more than a year” to stop them:  “And so, we think we will have the opportunity once we know that they’ve made that decision, take the action necessary to stop [Iran].” (CBS This Morning; September 11, 2012)

Building and testing a weapon would likely require that Iran expel IAEA inspectors who monitor Iran’s uranium production.  Experts believe Iran is unlikely to expel IAEA inspectors and leave the Nonproliferation Treaty any time soon.

  • Arms Control Association: Iran would not likely want to take the dramatic step of breaking out of the nuclear Nonproliferation Treaty (NPT) until it has enough material for several bombs—a point that it will not likely be able to reach for two years or more. Iran would then need time to produce the nuclear device itself (likely several months), which it has never done before, and then develop and probably explosively test a warhead that could fit on a ballistic missile, which would take still more time. (Arms Control Association; August 30, 2012)

The U.S. has assessed, however, that there is one pathway in which Iran would be compelled to expel IAEA inspectors and move forward with building a nuclear weapon.  According to former CIA Director Michael Hayden, when the Bush administration considered a bombing campaign against Iran, “the consensus was that it would guarantee that which we are trying to prevent: an Iran that will spare nothing to build a nuclear weapon and that would build it in secret.”