Iranian scientists have run computer simulations for a nuclear weapon that would produce more than triple the explosive force of the World War II bomb that destroyed Hiroshima, according to a diagram obtained by The Associated Press.
The diagram was leaked by officials from a country critical of Iran’s atomic program to bolster their arguments that Iran’s nuclear program must be halted before it produces a weapon. The officials provided the diagram only on condition that they and their country not be named.
The International Atomic Energy Agency — the Vienna-based U.N. nuclear watchdog — reported last year that it had obtained diagrams indicating that Iran was calculating the “nuclear explosive yield” of potential weapons. A senior diplomat who is considered neutral on the issue confirmed that the graph obtained by the AP was indeed one of those cited by the IAEA in that report. He spoke only on condition of anonymity because he was not authorized to discuss the issue.
According to the AP, the Iranian chart shows an explosive yield in the 50-kiloton range, making it three times as powerful as the atomic bomb dropped on Hiroshima in 1945. By comparison, the warheads carried by U.S. Minuteman III ICBMs have a reported yield in the 330kt range, while submarine-launched Trident D-5 missiles have warheads with a yield in the 1 megaton range.
Due to improved accuracy, U.S. nuclear weapons (and those of other nuclear powers) have decreased in explosive power over the past 30 years. The single warhead mounted on American Titan II ICBMs--retired from active service in 1986--had a yield of 10 megatons. At the height of the Cold War, the Soviet Union tested a massive bomb with a yield of 50-100 megatons, depending on its configuration.
Experts who have seen the diagram say its more of a performance chart than a blueprint for the actual device. Others claim its a bit optimistic in predicting the explosive force of an Iranian device, noting that North Korea's initial nuclear tests were duds, generating yields somewhere between 2-6 kilotons, on the low end of the scale for a Hiroshima-type weapon. Many analysts believe these results are indicative of devices that failed to detonate properly. Tehran could face similar difficulties in designing and testing their own nuclear weapons.
On the other hand, Iran has certain advantages in its nuclear development efforts. First, while Tehran's economy is far from robust, the Iranians can devote greater resources to their program, including money for outside experts. Over the years, there have been credible reports about nuclear scientists from Russia, North Korea and Pakistan making their way to Iran, and providing vital assistance. Similarly, Iran has benefited from the learning curve of other programs--most notably North Korea--improving chances for a successful first test, and a shortened development cycle.
As for the source of the diagram, it most likely came from Iranian opposition groups, who gave it to Israeli or American intelligence operatives. Our money is on the Israelis, who are facing a short-term decision on how they must deal with Iran's nuclear program. A U.S. leak is considered less likely, given the Obama Administration's insistence that Tehran is still many months away from critical "red lines," leaving room for more diplomacy.
There is also the possibility that the chart is some sort of Iranian disinformation effort, aimed at convincing the west that it is much further along in its nuclear development, and highlighting the potential consequences of military action against Tehran. However, the disinformation theory is also considered less plausible, since the diagram could influence Israel's decision to launch a military strike against Tehran's nuclear facilities. If Iran is in a final sprint to complete a bomb--as most intelligence analysts believe--they don't want to invite a near-term Israeli attack that could set back the program by months or years.
A final, albeit remote possibility, is that the leaked diagram is a warning from elements within the IAEA who have long believed that Iran is developing nuclear weapons, and are frustrated over the inaction by their agency (and the rest of the international community). According to the AP, the diagram is part of a computer simulation conducted in 2008 and 2009, five years after U.S. intelligence claimed that Iran had suspended most meaningful work on its nuclear weapons program.
That claim--made in an infamous 2007 National Intelligence Estimate--effectively thwarted potential action against Tehran by the Bush Administration. As Iran's nuclear program marches steadily forward, we can only wonder if our intelligence officials are being more honest about Tehran's current intentions than they were about the security debacle in Benghazi.