"Star Wars" America should really be buying

With North Korea and Iran achieving nuclear status, Americans naturally fear the rising potential for nuclear terrorism. As many presidential candidates point out, our ports remain unacceptably unsafe. But America needs more than just a firewall on its border. It needs defense in depth when it comes to detecting nuclear materials.

That I should make this argument more than five years after 9/11 is emblematic of our great failure of imagination since that tragic day, which turned far too much of our efforts and attention inward instead of outward. This is too narrow a perspective in a globalized world, where every nation is only as secure as every other nation to which it is connected by networks and trade.

During the Cold War, when America's primary nuclear threat was symmetrical, we were forced to--in Ronald Reagan's famous phrase--"trust but verify." But in a post-9/11 world, where transnational terrorists effectively elude threatened retaliation, emphasis logically shifts from the "trust" of arms control to the "verify" of active detection, preferably as distant from our shores--and population centers--as possible.

The good news is the technology exists today to accomplish much of this task, according to Oak Ridge National Laboratory, where last week senior scientists briefed me on the subject. America just lacks a coordinated research effort to bring it all together and address the remaining technical challenges. As one senior federal official who works nuclear counter-proliferation told us, "This is the number one security problem in Washington today."

At the end of the day, America needs both overt and covert capabilities to detect nuclear materials moved by sea: not just scanners at the port gate, but the capacity to monitor vessels surreptitiously. We need the public capability to signal our intent and interest, but also the secret version so interdictions can be made at the time and place of our choosing.

Ideally, defense-in-depth starts at overseas ports, both dockside and delivered from below by unmanned underwater vehicles. If we're just interdicting the material itself, better to do it at the port of embarkation. But say we're trying to figure out where the ship is headed, or maybe the device is too dangerous to approach in port.

If we're talking littoral waters, where such vessels skulk to avoid attention, then unmanned underwater vehicles are the way to go. They can be especially useful when targets stick to territorial waters to claim legal protection from outside inspection.

Once ships hit the open ocean, though, we face some of the toughest, almost James Bond-like challenges in getting close enough to detect without being noticed.

Seawater makes an excellent insulator, so if we want to detect thermal neutrons, we've basically got to achieve hull-to-hull contact with the suspected vessel. On the high seas, that means an approach speed somewhere in the range of 18 to 24 knots. That's very hard with an unmanned underwater vehicle.

If that's the case, then our forces might move on to special torpedoes able to keep up with the target or--better yet--deliver scanner-toting robots. These hull-crawling droids might be our only option to scan the entirety of a 400-foot ship, a process that can take up to eight hours depending on the nature of the shielding surrounding the material or bombs.

I know what you're thinking: now we've leapt past Bond right into George Lucas' fervent imagination.

Consider this: the Pentagon continues to spend tens of billions of dollars on strategic missile defense systems that still--after all these years--show no signs of working. Recently, the Bush administration started pushing missile defense onto countries like Poland and the Czech Republic, angering Russia in the process. Meanwhile, our government refuses to discuss a space arms treaty with China, which recently made its displeasure known with an anti-satellite weapon test.

Since we share these countries' fears of nuclear terrorism, why does our government continue to antagonize them in these counterproductive ways? Wouldn't it make a lot more sense to pursue the sort of "Star Wars" technology I'm describing here?

For a fraction of what it would cost to continue funding missile defense or fill space with dangerous strategic weaponry, America could readily field a vast fleet of underwater R2D2s to better manage this very real and near-term threat.

Next time you see your representative or senator, ask them what they're waiting for.