According to unconfirmed reports, two missile warheads capable of being armed with a nuclear weapon have been acquired by Iran’s Islamic Revolutionary Guard Corps.

Reza Kahlili, a former member of the Revolutionary Guards who became a spy for the CIA before defecting to the United States, charged in an article posted on FoxNews.com that the missile warheads were produced by a “joint military-industrial project” that included Iran, Pakistan, China, and Ukraine. According to Kahlili, “The Ukrainians provided the design for the warheads, while the Chinese and Pakistanis delivered the technology, machining and tooling. The Iranian Ministry of Defense coordinated the interface with all three.”

It would be surprising if the governments of these disparate countries would directly enter into such a high-risk joint venture to help Iran in violation of U.N. sanctions, but companies and proliferation networks from all three countries separately have sold Iran sensitive technologies in the past. And Iran has established a global smuggling network to acquire technology for its ballistic missile and nuclear programs. On Tuesday, an Iranian businessman operating in California pleaded guilty to conspiring to illicitly export missile parts from the United States to Iran.

Kahlili based his charges on reports from a mysterious group, the “Green Experts of Iran.” Curiously, North Korea, which is known to work closely with the Iranian regime on its ballistic missile program, is missing from the list of countries reportedly involved in the joint project. Last month, a U.N. panel of experts submitted a confidential report to the Security Council that charged that Iran and North Korea had regularly been exchanging ballistic missile technology, often trans-shipped through China.

There is no doubt, however, that the transfer of nuclear warhead technology for a ballistic missile delivery system to Iran, let alone intact warheads, would be a grave development. Accordingly, the U.S. and its allies would be foolish to discount the possibility of such transfers. Circumstantial evidence, if anything, suggests that the U.S. government should look more deeply into this possibility.

Iran’s missile development program appears to be even more aggressive than its nuclear weapons program. It is hard to believe that Iran would go to all the effort it is putting into its missile program—particularly for developing intermediate- to long-range missiles—only to arm the missiles with conventional warheads.

If the Iranians have already received technical assistance in constructing nuclear warheads for missiles—perhaps from North Korea, which is going down a similar path—or received intact nuclear warheads for missiles clandestinely from outside sources, it would explain their aggressive approach to ballistic missile development.

Discounting this possibility carries the risk that the U.S. and its allies will be plunged into an immediate national security crisis if Iran is shown to have deployed intermediate- or long-range ballistic missiles carrying nuclear warheads with little or no advanced warning. Such a surprise would present similar security risks to the U.S. and its allies as the unexpected Soviet transfer of such missiles to Cuba in 1962.

The U.S. intelligence community should scrutinize closely the full array of possibilities for Iran’s rapid development or acquisition of nuclear warheads for missiles. Everyone should hope that it is not already too late.