The decision by the US to shoot a missile at a dysfunctional spy satellite has provoked sharp protests from Russia and China and threatens to escalate competition over the control of space.

The US Navy made a successful strike using an SM-3 missile late Wednesday night, according to Pentagon officials. The missile was launched from the USS Lake Erie, located off the coast of Hawaii in the Pacific Ocean. The interception took place about 150 miles above the Earth’s surface.

The US military has claimed that the action was necessary for safety reasons—in particular, to prevent the satellite’s fuel tank from reaching ground intact. Many scientists and military experts have dismissed these arguments, however, pointing to a far more likely rationale: the attempt by the US to showcase its military capacity and send warning signals to potential adversaries, particularly China.

Little is known about the exact intended purpose of the satellite that was destroyed. It was launched in 2006 by the National Reconnaissance Organization (NRO), the section of the Pentagon responsible for spy satellites. It quickly ceased to function and would have fallen back to the Earth sometime in March.

In an indication of the importance the US government attributed to the missile launch, Defense Secretary Robert Gates personally gave the final order and closely monitored the progress of the missile.

The incident comes just over a year after China shot down one of its own weather satellites in a move that signaled the country’s threat to US dominance of space. The January 2007 test was condemned by the US and other powers. For its part, Russia has vigorously opposed US plans for constructing a missile defense system that would include radar systems near Russia’s European border.

Both Russia and China denounced the US missile strike, seeing it as a provocative act. Chinese Foreign Minister Liu Bianca said the US action “may influence the security of outer space and may harm other countries.”

People’s Daily, the Chinese state newspaper, wrote, “The Untied States, the world’s top space power, has often accused other countries of vigorously developing military space technology,” but did not shirk from using this technology itself. “The United States will not easily abandon its military advantage based on space technology, and it is striving to expand and fully exploit this advantage.”

The Russian Defense Ministry Information Department warned in a statement last week, “Under cover of discussions about the danger posed by the satellite, preparation is going ahead for tests of an anti-satellite weapon. Such tests mean in essence the creation of a new strategic weapon.” Andrei Kokoshin, former secretary of the Russian Security Council, said on Thursday that the missile launch meant a “new phase in the militarization of space.”

The decision to destroy the satellite was made only a few days after Russia and China issued a statement calling for an international ban on space weapons. The proposal, which is opposed by the US, would expand the Outer Space Treaty of 1967, which bans weapons of mass destruction in space.

The US military has official denied any military aim. However, its official explanation for why the action was taken is not credible. According to Joint Chiefs of Staff Vice Chairman James Cartwright, the sole motivation was public safety. In particular, he warned that if the satellite was not hit, a hydrazine fuel tank could reach the ground and leak the potentially harmful chemical.

It is highly unlikely, however, that the tank would have reached the Earth intact. Even if it did, it is even more unlikely that it could have harmed anyone on the ground.

Theodore Postol, a professor of science, technology and national security policy at the Massachusetts Institute of Technology, noted in comments on the NewsHour program on PBS Wednesday, “The idea that the hydrazine tank will survive to the ground really makes no sense.” He noted that the extremely high pressures and temperatures generated upon reentry would almost certainly split the tank open, dumping the fuel harmlessly into the atmosphere.

The Pentagon itself acknowledged that even minimal danger from the chemical, supposing the tank reached the ground, would cover only two football fields (about 10,000 square meters). Ivan Oelrich of the Federation of American Scientists noted that this amounts to about one ten billionth of the Earth’s surface. Over 70 percent of this surface is covered by water.

Large manmade objects fall to the earth from space at a rate of about 50 to 200 a year, but there have been no casualties from these objects since the beginning of the Space Age. The idea that the Pentagon would spend $60 million to counter the tiny risk involved is untenable. One commentator noted that if safety was the motivation the money would be better spent on improving roads and traffic lights, since far more hydrazine is transported on a daily basis on the ground than is contained in the spy satellite.

Some commentators have suggested that one motivation for destroying the satellite was concern over possible classified information it might contain, including encryption technologies. Jeremy Close, spokesman for European defense firm Astrium, noted, “If part of the satellite was to fall intact to the ground, or partially intact, it might yield valuable information about the type of cryptography used by the satellite to communicate with the ground.”

The main aim, however, was to demonstrate US military capacity. While the ability to destroy satellites is not new for the American military, the Pentagon has moved aggressively to develop its missile technology and flexibility. This is part of a broader attempt to dominate space.

This was the first live strike by the US Navy using its missile launch technology. The vessels used to launch the missile are easily deployed throughout the Atlantic and Pacific Oceans. It was as much a display of versatility as it was of capacity.

The January 2007 Chinese anti-satellite test was viewed with great concern by the US military. Michael Mosley, the US Air Force chief of staff, compared the incident to the Soviet launching of the first satellite in history, Sputnik, in 1957.

The American military relies heavily on satellites in everything from communications to targeting. The US sees space as its domain and is strongly opposed to any other country developing the ability to control the ultimate “high ground.”

Domination of space has been a longstanding ambition of the American ruling class, going back at least to Lyndon Johnson, who noted that from space “total control of the Earth may be exercised.” The so-called “Star Wars” program of missile defense during the Reagan administration was part of this ambition, though it was largely unsuccessful.

Control of space and missile defense was an early priority of the Bush administration. In 2001, future Defense Secretary Donald Rumsfeld headed the Commission to Assess US National Security Space Management and Organization. The panel concluded, “It is in the US national interest to...use the nation’s potential in space to support its domestic, economic, diplomatic and national security objectives; develop and deploy the means to deter and defend against hostile acts directed at US space assets and against the uses of space hostile to US interests.” The panel warned ominously of a “Space Pearl Harbor.”

In 2004, the Air Force produced a document calling for maintaining “space superiority,” which it defined as the “freedom to attack as well as the freedom from attack.” In 2006, the Bush Administration released its National Space Policy, which insisted on the necessity for “space control” and the rejection of “new legal regimes of or other restrictions that seek to prohibit or limit US access to or use of space.”

As the American ruling class seeks to bolster its global position through the use of military force, control over space—which by its very nature is a global frontier—will assumer ever greater importance.