Among U.S. Secretary of Defense Robert Gates' proposed changes to the 2010 U.S. defense budget, announced on April 6, were a series of increases and cuts in ballistic missile defense (BMD) programs. Taken as a whole, these adjustments mark a significant shift in the nature of BMD deployment, including an overall cut of $1.4 billion from the Missile Defense Agency. These cuts are consistent with President Barack Obama's platform of being committed to "proven, cost-effective" BMD, and are being touted as enabling the programs to focus on the threat of missile launches from "rogue" countries like Iran and North Korea. BMD is essentially a defensive weapons system designed to intercept ballistic missiles. Ballistic missile interception can theoretically be done at three periods of the missile's flight: in the terminal phase (as it descends towards the earth), in midcourse, and in the boost phase (right after launch).
Current technology permits the interception at the midcourse and terminal phases, but boost-phase interception has proved to be much more difficult, mainly because of the extremely short period of time it allows to detect, acquire and track the missile and plot an intercept before it enters the later phases of flight (more about this below). In laying out Gates' funding priorities, the budget favors the more mature technologies of terminal-phase and midcourse interception, which are either already fielded or in the process of being fielded.
But this comes at the cost of boost-phase and other more ambitious technological development programs — including space-based assets — which would require longer-term funding and support before tangible results could be achieved. For Gates, these more long-range programs have been pushed forward too aggressively, before the technology could mature. They are more high-risk by nature and, for Gates, an inefficient and an inappropriate allocation of funds given the current wars in Iraq and Afghanistan. While there are technical reasons for these choices, Gates has more in mind than just a sheet of specifications and test results.
There are four mature BMD systems that are operational or in the process of being made operational: Aegis/Standard Missile-3 (SM-3), Terminal High Altitude Area Defense (THAAD), Patriot Advanced Capability-3 (PAC-3) and Ground-based Midcourse Defense (GMD). The Aegis/SM-3 system is capable of intercepting ballistic missiles during parts of the ascent and descent phases. This system has already been deployed on 18 American guided-missile cruisers and destroyers, and two Japanese Maritime Self-Defense Forces warships and is operationally proven (though as an anti-satellite weapon rather than a BMD interceptor).
The Aegis/SM-3 has been one of the most successful BMD programs in the U.S. inventory, and Gates' proposal would increase funding for the SM-3 program and upgrade an additional six warships with the system (double the three announced earlier this year for the Atlantic fleet). The THAAD system is mobile (designed to be deployed anywhere in the world) and is capable of intercepting a ballistic missile in its final midcourse descent and in its terminal phase, both inside and outside the atmosphere. The first THAAD battery — Alpha Battery of the 4th Air Defense Artillery Regiment at Fort Bliss in Texas — was activated last year and is in the process of being fully equipped.
Meanwhile, testing continues at the Pacific Missile Range in Hawaii (a test there in March marked the system's latest success). After poor test performance in the 1990s, the program restarted testing in 2005 and has shown marked improvement. It is now considered technologically mature.
Gates curtailed funding for additional GMD interceptors in Alaska but made no comment on the much more politically complicated issue of deploying them to Europe. With his 2010 budget, of course, Gates has entered into a domestic battle with Congress over the future shape and orientation of the entire Department of Defense, not just BMD. Although part of that reorientation, the European GMD effort will be decided in the context of larger negotiations with Russia and policy choices made by the Obama Cabinet as a whole. But taken as a whole (and even without a GMD deployment in Europe), this combination of technologies offers a tiered BMD capability in the later phases of ballistic flight.
It is this sort of layered, overlapping combination of capabilities that is considered necessary to provide a truly reliable BMD shield. In addition, for the most part, these are the programs on which other countries like Japan and Israel have been cooperating with the United States. The impetus for pursuing boost-phase intercept capability is by no means gone, however. Midcourse and terminal phase interceptions are fraught with their own challenges, including the possibility of having to deal with decoys in the latter part of the midcourse phase and multiple independently targetable or maneuverable re-entry vehicles. Additionally, debris from a successful intercept in the terminal phase may still hit the area being targeted by those who launched the missile.
Thus, it remains desirable for the Pentagon to seek technology that will push the intercept point closer to the time and place of launch, if not on the actual territory of the country launching the missile. The boost phase is when the missile is both at its slowest in the trajectory and the most visible, given the unmistakable infrared signature of the engine plume. Also, if the missile is intercepted in this phase, the debris falls far from the intended target. As alluded to earlier, however, intercepting a missile during its boost phase is extremely difficult. At most, the boost phase lasts only a few minutes, and terrestrial-based interceptors also need time to boost to altitude as well (acceleration is a key design consideration).
Additionally, interceptors and sensors must be based relatively close to the area from which the missile is launched, so their positioning is highly dependent on the accessibility of territory or waters nearby.
In Gates' 2010 budget, however, funding for a second ABL airframe was cut and the program was reduced to more of a long-term research and development effort. These technical challenges will still be explored, but if Gates has his way, operational fielding of a boost-phase interceptor will be delayed — perhaps significantly — and some programs previously under consideration may never see the light of day as a weapons system. After all, if the concern is the current "rogue" threat from North Korea and Iran, then the ballistic missiles targeted would be highly vulnerable to air strikes while still on the launch pad. In a larger sense, Gates does not see the more advanced challenges of BMD as near-term problems. They are all desirable capabilities in the long run, but Gates has made his tenure about choices and priorities. His funding proposals for BMD reflect choices to field only mature programs while taking $1.4 billion from the Missile Defense Agency budget to put toward the current fight in Iraq and Afghanistan. And this is a fight that Gates considers not only the current one but also the kind in which American forces will be engaged in the foreseeable future.
Next: The 2010 defense budget and the fighter mix.