So far, U.S. military spacecraft are used only for gathering and relaying information. There are indications, though, that the Bush administration plans to “weaponize” space. The clearest signal came in January 2001, even before the new president was sworn in, when a commission chaired by now-Defense Secretary Donald Rumsfeld declared that the United States is more dependent on space than any other nation and “must develop the means to deter and defend against hostile acts in and from space.” Failure to protect U.S. satellites, the commission warned, could lead to a “Space Pearl Harbor.”

Opponents derided this conclusion as a provocative strategy that could precipitate a new arms race. We asked Charles Pea, senior defense policy analyst at the Cato Institute, a libertarian research group based in Washington, to explain why he thinks putting weapons in space is a bad idea.

Charles Pea I agree with the commission that our satellites in space are vulnerable. But at the same time, nobody has any way to exploit that vulnerability. In Pearl Harbor, the Japanese had airplanes that could attack ships. But even if Russia or China wanted to build an anti-satellite weapon, they couldn’t feasibly do so for 20 to 30 years. We shouldn’t waste money on weapons that will be obsolete by then.

Popular Science But even if there isn’t yet a lot to fear, what’s the harm in launching weapons to protect our satellites?

CP The last thing we want to do is to provide incentives that don’t exist now for other countries to develop weapons that might jeopardize our space assets. We have more to lose than anyone else by taking an offensive posture.

PS Do you think we should ever weaponize space?

CP If history is any indicator, it may in fact be inevitable. I just don’t think that now is the right time to make that move.