ext year will mark the 25th anniversary of U.S. President Ronald Reagan’s call for a national defense against ballistic missiles. For anyone who ever doubted the difficulty of building effective missile defenses, the fact that a quarter-century has passed without such a system becoming fully operational should be a wake-up call. Interception of ballistic missiles is a very challenging mission, and not just because of the technologies involved.

U.S. President George W. Bush’s administration is relearning that lesson right now as Congress moves to scale back the six-year, $4 billion plan to deploy a defensive radar and interceptors in Eastern Europe. The problem isn’t so much the technology, which is reasonably mature and much less capable than the orbital shield President Reagan once envisioned. The problem is that no one knows whether all the political forces that come into play can be reconciled to permit deployment on European territory.

The Russian government has vociferously objected to having ground-based missile defenses on its doorstep, and there are widespread doubts elsewhere in Europe about whether local governments should go along with the plan.

While most of the objections seem to be grounded in misconceptions about the goals of the Bush administration’s relatively modest system, they underscore how politics can interfere with defensive efforts even when necessary technologies are available.

Against that backdrop, an important debate is playing out on Capitol Hill over another facet of the administration’s program: the plan to build a Space Tracking and Surveillance System (STSS) for monitoring ballistic warheads from orbit. The satellites in the STSS constellation would carry infrared and visible-light sensors capable of sorting out and continuously tracking hostile ballistic warheads throughout the 80 percent of their trajectory known as midcourse.

Midcourse is the time between when a missile launches out of the atmosphere and when it re-enters, the phase of flight where heat and other emissions are so muted that detection is difficult.


United States doesn’t possess a system for continuously tracking ballistic warheads in midcourse, and that makes effective interception much less likely no matter what defensive weapons and sensors await the warheads when they enter the terminal or re-entry phase of their trajectory.

STSS would have the sensitivity to track the warheads, discriminate them from nonthreatening decoys and debris, and hand off the tracks to ground-based interceptors equipped with similar sensors.

The prospects for successful interception would be greatly improved over relying solely on ground-based sensors such as the radar that the Bush administration wants to build in Eastern Europe. The space-based sensors also could monitor other traffic in space, such as anti-satellite weapons. So the same constellation would greatly improve awareness of hostile ballistic missiles and other orbital objects posing a threat to national security.

But there is a problem, and it is mainly political. Although steady progress has been made in building the first two STSS satellites so that they can be launched in 2008 and demonstrate their capabilities, Congress wants proof the system works before funding an operational constellation. The delay would result in a dismantling of the engineering team that built the satellites, raising costs and pushing the date for an operational system further into the future.

It isn’t hard to understand why Congress might want to wait; military space programs have had numerous problems in recent years, and legislators have become skeptical about the promises they get from program managers. Beyond that, key authorizers and appropriators are always looking for unneeded money that can be applied to other purposes.

But in the case of STSS, the consequences of delay are onerous if not downright scary. As of today, there is no global system for continuously tracking Russian or Chinese or North Korean or Iranian ballistic warheads during most of their flight, and nobody can say for sure if we will overcome opposition to the deployment of less capable ground-based sensors on foreign territory.

So there is a big gap in plans for dealing with the most destructive military threat our nation faces.

The smart thing to do would be to simply fund the STSS program at the level requested by the Bush administration, avoiding delays is the best option we are likely to have for tracking and destroying hostile missiles. The amount of money placed at risk would be small, while the potential reduction in danger to America and its allies would be considerable.

When you compare the minor risks of staying on track with the huge risks of delaying, it isn’t hard to see the right path forward.

Loren Thompson is chief operating officer of the Lexington Institute.