A recent conversation with Ron Kadish, former head of the U.S. Missile Defense Agency (MDA) and now an adviser for Booz-Allen Hamilton, underlined the fact that ballistic missile defense (BMD) advocates are more confident in their basic technology. However, Kadish says, “You can’t declare victory.” In his view it is important to keep deploying systems and developing technology to stay ahead of threats.

He notes that North Korea has developed missile technology and is using it as a negotiating tool “despite our efforts against the proliferation of missiles and weapons of mass destruction.” Kadish argued for continuing the plan to deploy radars in the Czech Republic and Ground Based Interceptor (GBI) missiles in Poland. “People don’t realize that it’s not there to protect Poland and the Czechs. They’re going out on a limb, as friends, to allow us to protect ourselves.” He also advocated continuing work on the high-performance Kinetic Energy Interceptor missile.

None of these initiatives is being pursued by the Obama administration. That’s not to say that missile defense is dead or permanently on the back burner. Rather, shifts in doctrine and technology may be driving BMD toward a maritime-centric model.

For example, it seems likely that whatever new surface combatant follows the Navy’s trio of Zumwalt-class destroyers will have a BMD-capable radar suite, inherently better adapted to the role than today’s Aegis. Programs to upgrade the Aegis system and the associated Standard Missile to improve their BMD capability have not been terminated. Links are being reinforced between one of the MDA’s successes, the transportable TPY-2 X-band radar and the SM-3 missile, including development of a land-based version.

This development is in line with a strategic shift in U.S. BMD to ascent-phase intercept (API). Aimed mainly at medium- and intermediate-range missiles, API fits between the boost and mid-course phases in the high-endo- and low-exoatmospheric realm. The engagement takes place before the target missile can deploy decoys, and does not need such a high-performance interceptor as a mid-course shot. Warning and response times, however, are less stressing than a boost-phase engagement. What it does require is a forward-located interceptor.

The program to improve the Standard Missile’s suitability for BMD continues. Raytheon’s SM-3 Block 1B cleared its critical design review in July, paving the way for a first test flight in 2010. It features a two-color seeker and new thruster system for its kill vehicle, and is expected to be better able to distinguish between decoys and real targets than the in-service Block 1A.

The U.S. and Japan are funding the SM-3 Block IIA, which has a larger motor: The entire missile is expanded to fill the 21-in. diameter of the launch tube. Burnout velocity is up to 60% higher than that of the Block 1B. The missile is expected to fly in 2012 and enter service in 2015.

Another missile development for the Navy is the sea-based terminal capability, aimed to a great extent at the threat of antiship ballistic missiles under development by China. The first phase in the program was deployment of new software and SM-2 Block IV missiles on board Aegis ships. The third and latest test of the Block IV took place in March off Point Mugu, Calif. The next phase is the integration of a new interceptor missile.

Ship modernization is proceeding apace. The Navy announced in July that the Ticonderoga-class cruiser USS Lake Erie completed the first installation of the BMD 4.0.1 configuration of Aegis, including the new BMD Signal Processor. This is an upgrade beyond Block 3.6.1, which supports the terminal-intercept SM-2 Block IV missile, and will allow ships to take advantage of the SM-3 Block 1B high-altitude interceptor. Japan is modifying four Aegis destroyers with the BMD midcourse system and will equip them with the Block IIA missile.

The merging of land- and sea-based BMD is following two tracks. One of these is the use of forward-based TPY-2 radars to cue and even target sea-launched missiles. An MDA brief last year presented an analysis that showed with X-band radar cueing, sea-based SM-3 Block IIA missiles could cover Europe against an attack from Iran, and substitute for land-based missiles in central Europe.