Another major development on the national-security front today: the US plan to shoot down one of its own spy satellites.

President Bush, acting on the advice of his national security advisers, has decided to attempt to shoot down a malfunctioning spy satellite that is expected to crash to Earth early next month, a spokesman for the National Security Council said today.

NSC spokesman Gordon Johndroe said the president made the decision within the past week and asked the military to come up with plans to destroy the satellite.

Johndroe said that decision, which will be explained at a Pentagon news conference this afternoon, was based on the fact that the satellite is carrying substantial amounts of a hazardous and corrosive rocket fuel, hydrazine.

The satellite was launched in December 2006 but soon lost contact with ground control. Information about the spacecraft is classified, but experts believe it is the first of a new generation of smaller and more precise spy satellites.

Johndroe said the satellite would be destroyed “as it comes to Earth,” which is expected to occur in several weeks.

The US may also be concerned about sensitive technological components falling to the wrong hands.

Some military experts say the Pentagon may be worried the satellite’s top secret spy technology might survive reentry into the atmosphere and end up in the wrong hands. General Cartwright rejected that speculation.

“There is some question about the classified side of this,” he said. “That is really not an issue. Once you go through the atmosphere, and the heating and the burning, that would not be an issue in this case. It would not justify using a missile to take it and break it up further.”

Taking down the satellite is a sensitive issue because of the controversy sparked when China shot down one of its defunct weather satellites last year, drawing criticism from the United States and other countries. The Pentagon said it has briefed other countries about its plans.

Which is well and good. But remember that this comes almost immediately after Russia and China proposed a treaty banning space-based weapons systems and those designed to attack objects in orbit.

The Bush Administration, which seeks to extend the US “command of the commons” to outer space, opposes the treaty.

I can’t help but imagine that the Chinese and the Russians, let alone many other observers, find the timing of this announcement suspicious. After all, what might better demonstrate the importance of anti-satellite weapons than a potential environmental danger from a malfunctioning satellite? And it does give the US an opportunity to flex its muscles.

But even if the timing is completely innocent–and I see no reason to doubt that the decision stems from legitimate concerns–its implications are likely to reverberate in an already deteriorating environment for US-Russian, and possibly Sino-US, relations.