The likelihood of the U.S. establishing a fixed Ground-Based Midcourse Defense (GMD) missile interceptor site in Poland appears to be waning as the Pentagon is more sharply focused on the quick fielding of a land-based SM-3 system to protect Europe from an Iranian ballistic missile threat.

Marine Corps Gen. James Cartwright, vice chairman of the Joint Chiefs of Staff, says part of the rationale behind capping the number of operational three-stage Ground-Based Interceptors (GBIs) (GMD’s missile segment) was a miscalculation of the intercontinental ballistic missile threat. “The reality is it did not come as fast as we thought it’d come,” he told an audience at the Space and Missile Defense Conference 2009 here last week. Air Force Lt. Gen. Henry (Trey) Obering, the Missile Defense Agency (MDA) director through 2008, said the ICBM threat was expected to materialize in 2015, and that drove the time line for establishment of the European missile field. Cartwright did not cite a new date by which intelligence experts predict an ICBM threat could materialize.

Iran has demonstrated a space launch capability and, despite a third-stage failure of North Korea’s Taepo-Dong 2 during a recent test, experts at the conference this week say Pyongyang is making some headway. Uzi Rubin, retired Israeli general officer and expert on the threat, says the Iranians have made considerable headway with solid rocket motors. And the pace of ballistic missile-testing in Iran is impressive, he says.

Still, the 30 GBIs—26 at Ft. Greely, Alaska, and four at Vandenberg AFB, Calif.—are deemed sufficient to counter the “rogue” threat of a long-range ballistic missile attack on the U.S. from North Korea or Iran. “That is a heck of a lot more than [needed for] a rogue,” Cartwright added. An X-band tracking radar, which is slated for the Czech Republic, is needed in the region regardless of where the interceptors are based, he noted.

Despite a rush from then-President George W. Bush to establish a site for 10 two-stage GBIs in Poland in advance of the 2015 threat, the proposal has suffered setbacks. It has not been ratified there. And it has sparked ire from Russia, which sees it as destabilizing and threatening to Moscow’s nuclear deterrent capability at a time when Washington is negotiating a follow-on to the Strategic Arms Reduction Treaty (Start), which expires at the end of the year. Cartwright says it would take five years from approval until deployment of the GBIs in Poland.

The Obama administration has begun a wholesale review of what is needed to defend allies in Europe and U.S. forces there from an attack. This shift away from GBIs could represent an attempt by the White House to continue fielding missile defenses, but also to steer clear of the fast and long-range GBIs as well as the very-high-speed and mobile Kinetic Energy Interceptor. Termination of KEI was proposed by Defense Secretary Robert Gates in the Fiscal 2010 budget, and program execution was cited among the reasons. The mobile GBI and KEI could be viewed as more destabilizing for regional powers such as Russia and China. One retired senior Pentagon official suggests KEI could have been a “sacrifice” to get Russia to agree to some other form of missile defenses in Europe and in light of the Start talks.

“We have to walk a fine line as we deploy and develop a system to counter North Korea,” said U.S. Air Force Gen. Kevin Chilton, head of Strategic Command, in a speech here last week. Deployment of missile defense systems that could be seen to threaten Russia’s and China’s nuclear deterrent could spark an arms race that is unaffordable in this recession, he noted.

Raytheon’s ship-based SM-3 Block IA has been universally hailed by Pentagon officials as a success because of recent test-intercepts and the impromptu use of the three-stage missile to destroy a wayward intelligence satellite in February 2008. The MDA is planning to open a program office to manage the development of a land-based version here, where many of the agency’s program offices are located. The Army will likely operate it. SM-3 has a shorter range than the GBI, though program officials are working to increase the velocity at burnout to provide more engagement flexibility.

Using the 14.5-in.-dia. SM-3 Block IB, which is in development, six or seven batteries would be required to provide coverage to Europe. The IB will include a new divert-and-attitude-control system as well as a new two-color seeker. Michael Booen, a vice president at Raytheon, says the system could achieve initial operational capability in 2013 (far sooner than the fixed GBI site in Poland); the MDA requested $50 million to start work in Fiscal 2010. The IB is designed to counter short- and medium-range ballistic missiles and will likely provide some capability against intermediate-range threats, says Dean Gehr, Raytheon’s SM-3 program lead. It is not seen as intimidating to Russia’s long-range missiles, and thus could be more politically palatable.

Cartwright says the land-based SM-3 could provide an interim defense for Europe against the more quickly proliferating threat of short- and medium-range missiles. “You look at an alternative [to GBI]—SM-3 or something else—and what we are seeing is that then it is only going to be two years to field. So, I can make a decision about that now, have a hedge [against the threat] and then, if GBI is actually required, I’m still OK because I’ve got something fielded,” and can proceed with GBI at a later date, Cartwright told Aviation Week after his speech. “What is real is the regional threat.”