Conventional wisdom has it that Iran will be capable of fielding an intercontinental ballistic missile by the middle of the next decade. Iran’s space program also has charted serious advances since the Islamic Republic (with Russian help) became the first Muslim spacefaring nation in 2005. There is real reason to believe that—given the similarities between space launch and ballistic missile technologies—the progress Tehran has made on one could lead to quantum leaps in the sophistication of the other.

A long-range Iranian missile capability, in other words, could materialize much sooner than currently projected. And according to a new report by the International Atomic Energy Agency, the Islamic Republic is now working to marry its ballistic missile arsenal with its nuclear program, fashioning a missile system capable of carrying a nuclear warhead.

Our security depends in large measure on beating Iran to the punch. If the U.S. succeeds in deploying missile defenses capable of intercepting Iranian long-range missiles before they are developed, it will help protect itself, its allies and its troops from the menace posed by a nuclear Iran. But if missile defenses become operational after Iran’s long-range missile capability does, both America and its allies will find themselves vulnerable to nuclear blackmail, or worse, from the world’s leading state sponsor of terrorism.