After several attempts, the People's Republic of China has successfully tested an anti-satellite weapon. The kinetic-energy "kill vehicle" destroyed its target - one of Beijing's own aging weather satellites - orbiting over 500 miles above Earth.

This is bad news. For starters, it calls into question China's mantra that its unprecedented military buildup is for self-defense, that its rise to world power will be peaceful. It's a threat to no one - and it will only use space for peaceful purposes.

Not surprisingly, after the Jan. 11 test was confirmed late last week, the United States, Japan, Britain, Canada and Australia all condemned the Chinese anti-satellite (ASAT) missile launch.

A White House National Security Council spokesman said last Thursday: "The U.S. believes China's development and testing of such weapons is inconsistent with the spirit of cooperation that both countries aspire to in the civil space arena."

So why is the Chinese KT-2 "satellite-killer" launch - the first ASAT test since America and the Soviet Union conducted tests in the 1980s - causing so much "final frontier" heartburn? Well, for a lot of good reasons - at least from an American perspective:

• The missile test, launched from the Xichang Space Center in central China, was unannounced and appeared to have taken place without the prior consultation of other countries with space-based assets, such as the United States.
  
  
• The destruction of the target created a major debris field - "space junk": hundreds of metal objects that could damage other space vehicles that come into its path, including satellites or even the space shuttle.
  
  
• China has long pushed for a ban on space-based weapons and voiced strong opposition to any "weaponization of space" at the United Nations - and elsewhere. This launch totally flies in the face of all that rhetoric.
  
  
• The successful test means China not only can track but also can destroy low-Earth-orbit satellites, such as weather, communications, surveillance and global-positioning satellites. This could seriously hamper U.S. military operations.
  
  
• The Pentagon believes Beijing is developing laser and/or radio-frequency weapons, which would enhance its ASAT capabilities. Thus, China could eventually threaten other critical orbiting military satellites, including high-value spy-sats. Beijing may have "lazed" - pulsed with a high-intensity laser - one of our imagery satellites last year . . .

Adding to the consternation has been China's silence - even denias - about the launch. Beijing's lack of transparency about its space programs, especially since it's run by the military, has led some to express concerns about an impending Star Wars-like arms race.

The problem is only exacerbated by recent reports that Russia will cooperate with the Chinese space program. Moscow says it won't transfer sensitive technology, but its record of advanced-weapons sales to China isn't comforting.

So why did China launch the ASAT now? No real telling. Could be a little provocative chestbeating. Or a gambit by Beijing to get Washington to enter negotiations on a ban on weaponizing space.

Facing this new challenge, America should continue to deflect regular Chinese advances for cooperation with NASA. Nearly all space technology can be applied to both civilian and military purposes.

And the FBI should redouble its counterintelligence efforts against Chinese spies that may be targeting U.S. space-related high-tech efforts in government, industry and universities.

Beijingis serious about space. It put taikonauts (Chinese astronauts) in space in 2003 and 2005, expects to launch 100 civilian/military-use satellites in the next five to eight years, and plans to put a man on the moon by 2010 and a moon rover over there by 2012.

The PRC also understands U.S. military dependence on our space infrastructure. Without spy and communications satellites, our forces would be left essentially deaf, dumb and blind - on a suddenly level battlefield with a (previously) less capable adversary, a shrewd example of the promise of asymmetric warfare.

Bottom line: China is on a trajectory to challenge Washington (and Moscow) for preeminence in space. The ASAT test is a wake-up call. Protecting our space assets - and freedom of action on the high frontier - must be central to our national security strategy.

Peter Brookes is a columnist forThe New York Post, a Heritage Foundation senior fellow and author of "A Devil's Triangle: Terrorism, WMD and Rogue States."