The latest encouraging news came Thursday courtesy of the Misssile Defense Agency. The Airborne Laser prototype aircraft this week found, tracked, engaged and simulated an intercept with a missile seconds after liftoff. It was the first time the Agency used an "instrumented" missile to confirm the laser works as expected. Next up this fall will be the first live attempt to bring down a ballistic missile, but this test confirms how far along this innovative effort has come.

Along with space-based weapons, the Airborne Laser is the next defense frontier. The modified Boeing 747 is supposed to send an intense beam of light over hundreds of miles to destroy missiles in the "boost phase," before they can release decoys and at a point in their trajectory when they would fall back down on enemy territory. It's a pioneering use of directed energy in defense. The laser complements the sea- and ground-based missile defenses that keep proving themselves in tests.

Yet the Obama Administration isn't buying it. Funding for missile defense was cut in the 2010 budget by some 15%—$1.2 billion to $1.6 billion, depending on how you calculate it. The number of ground-based interceptors was reduced. The Missile Defense Agency's budget for the Airborne Laser is to be slashed in half, and Secretary of Defense Robert Gates pulled the plug on buying a second plane. The Pentagon says the program will have three tries to hit a live missile, or be killed altogether.

As the Administration keeps defense spending growth flat, while breaking the bank on its domestic priorities, Secretary Gates has to make hard choices. But he might try harder to convince his boss at the White House that Star Wars isn't a sci-fi fantasy. That's what critics used to say about stealth aircraft as well.

With time, and inevitable setbacks, the technology to make layered missile defenses a reality is being proven to work. The Airborne Laser could be—unless prematurely vaporized—an important part of a system to protect America and its allies from rogue states and their nuclear missiles.