But what if Iran buys one or two nuclear warheads from North Korea? The government in Pyongyang has already conducted three nuclear tests and claims that it has nuclear warheads that fit on its No Dong medium-range ballistic missiles. If that claim is true, then mounting the warheads on Iran’s Shahab missiles, which are copies of the North Korean ones, would present little problem. After all, Iran has collaborated with North Korea on missile design for more than a decade.

These off-the-shelf weapons would leave virtually no window of opportunity for a pre-emptive attack by the West and its allies. The warheads could arrive in Iran on a plane in the middle of the night and be immediately fitted onto Iranian missiles. Iran would not have to actually use these missiles to have a deterrent. It could renounce the Non-Proliferation Treaty and flaunt its nukes, as North Korea has done for seven years without suffering a military attack by the U.S. Indeed, such a fait accompli would give Iran the same potential for nuclear retaliation as North Korea.

Do we know for sure that North Korea has nuclear warheads it could transfer to Iran? There is little doubt that the country has the means to produce between three and six nuclear bombs annually. In 2011, North Korea invited a former director of the Los Alamos National Laboratory, Siegfried Hecker, to inspect a state-of-the-art uranium-enrichment plant at Yongbyon, with just such a capability. According to a Feb. 13 report by the Congressional Research Service, U.S. intelligence believes that, in North Korea, “it is likely other, clandestine enrichment facilities exist” to produce fissile material for bombs.