As we've noted in previous posts, creating a nuclear capability means more than building a bomb. Along with the weapon, nations attempting to join the nuclear club must also have delivery platforms, and a means for identifying potential targets/aim points.
Analyzing current activity in Iran, there is no doubt that the mullahs are pressing toward a full-fledged nuclear weapons capability. Work on an "Persian bomb" is continuing, with Iranian scientists pursuing both uranium and plutonium-based weapons. In terms of targeting, Iran began purchasing satellite imagery of potential aim points (including Israeli cities) in the late 1990s. More recently, they've been upgrading their satellite downlink and imagery capabilities, allowing them to receive higher-quality shots from outside suppliers.
Iran is also developing missile systems, capable of delivering nuclear warheads to targets in the Middle East--and beyond. We've written extensively on the SHAHAB-3, the medium-range missile (based on a North Korean design) that has the range to hit Israel. Since becoming operational in late 2004, the SHAHAB-3 has been deployed at multiple locations inside Iran, using a variety of basing options. Many of Iran's SHAHAB-3s (and their mobile launchers) are stored in large underground complexes, making them difficult to track--and potentially target, since the missiles would be dispersed away from garrison during contingency operations.
But Tehran has never been completely satisfied with the SHAHAB-3. The missile's range maximum range extends just past Israel and its payload is limited. Iran has working on missiles with a longer range and capable of delivering a larger warhead. There have been reports of SHAHAB-4/5 programs, designed to field an intermediate range ballistic missile (IRBM), allowing Iran to potentially target portions of Southern Europe and India as well. It is unclear how much progress Tehran has made on its IRBM program.
Of course, it would be easier for Iran to simply purchase an existing IRBM from an outside source, and there are growing indications that Tehran has done just that. In December, German intelligence sources told the newspaper Bild that Iran had obtained a limited number of BM-25 IRBMs from North Korea. The BM-25 is based on a 40-year-old Russian submarine-launched ballistic missile (SLBM), the SS-N-6. North Korean land-based versions of the BM-25 are believed to have a range of 2500-4000 km, depending on payload. That would allow the Iranians to target all of the Middle East, a large portion of the Asian subcontinent, and much of Europe.
The presence of BM-25s in Iran has not yet been confirmed. However, with Tehran's expertise in the SHAHAB-3 (and potential assistance from North Korea), Iranian engineers could assemble and test-fire a BM-25 before the end the year--the very period when European leaders will decide what action (if any) they will take regarding Iran's nuclear program.
One more note: from inception, the SS-N-6/BM-25 was designed to carry a nuclear warhead. Acquisition/integration of the BM-25 could give Iran a ready option for the first "Persian bomb" whenever it is built. With the SHAHAB-3, the Iranians would probably have to downsize the warhead to mate it with the missile, creating another delay in Iran's nuclear program. The BM-25 could probably accept an early-model Iranian warhead without modifications, allowing Iran to have a nuclear missile force much sooner.
And that raises the central question: just how far along is Iran in its nuclear program. Some intelligence analysts believe Tehran may be a decade away from actually fielding a nuclear device, but the "sudden" acquisition of the BM-25 may contradict that assessment. If Iran was 8-10 years away from having a working bomb, why the sudden rush to obtain a longer-range, nuclear-capable missile? Both Tehran and Pyongyang may be trying to beat potential sanctions, but the missile deal also suggests other scenarios: (1) Iranian efforts to develop an indigenous IRBM have been unsuccessful, and (2) Iran needs a nuclear-capable missile because it will have a warhead much sooner than 2016.