The Obama administration on Monday unveiled a space policy that renounces the unilateral stance of the Bush administration and instead emphasizes international cooperation, including the possibility of an arms control treaty that would limit the development of space weapons.

In recent years, both China and the United States have destroyed satellites in orbit, raising fears about the start of a costly arms race that might ultimately hurt the United States because it dominates the military use of space. China smashed a satellite in January 2007, and the United States did so in February 2008.

The new space policy explicitly says that Washington will “consider proposals and concepts for arms control measures if they are equitable, effectively verifiable and enhance the national security of the United States and its allies.”

The Bush administration, in the space policy it released in August 2006, said it “rejects any limitations on the fundamental right of the United States to operate in and acquire data from space,” a phrase that was interpreted as giving a green light to the development and use of antisatellite weapons.

The policy also stated that Washington would “oppose the development of new legal regimes or other restrictions that seek to prohibit or limit U.S. access or use of space,” a phrase that effectively ruled out arms control.

In secret, the Bush administration engaged in research that critics said could produce a powerful ground-based laser, among other potential weapons meant to shatter enemy satellites in orbit.

By contrast, the Obama policy underlines the need for international cooperation. “It is the shared interest of all nations to act responsibly in space to help prevent mishaps, misperceptions and mistrust,” the new policy says in its opening lines. “Space operations should be conducted in ways that emphasize openness and transparency.”

Peter Marquez, director of space policy at the White House National Security Council, told reporters on Monday that the policy was reverting to a less confrontational approach that the United States had championed in the past.

“The arms control language is bipartisan language that appeared in the Reagan policy and George H. W. Bush’s policy and the Clinton policy,” Mr. Marquez said in a White House briefing. “So we’re bringing it back to a bipartisan agreed-upon position.”

Jeff Abramson, a senior analyst at the Arms Control Association, a private group in Washington, said the new policy “sets the stage for progress in space arms control — without getting into specifics.”

For many years, diplomats from around the globe have gathered in Geneva to hammer out a treaty on the “prevention of an arms race in outer space,” which would ban space weapons. Arms control supporters say that China and Russia have backed the process, and that the United States during the Bush administration dragged its feet.

In 2006, John Mohanco, a State Department official, told the diplomats in Geneva that as long as attacks on satellites remained a threat, “our government will continue to consider the possible role that space-related weapons may play in protecting our assets.”

Now, the Obama administration has stopped the saber-rattling and started what might end in a new kind of peaceful accord — though with plenty of caveats and vague conditions.

Although the new policy calls on the United States to “lead in the enhancement of security, stability and responsible behavior in space,” it also says that any resulting arms treaties would have to be equitable, verifiable and enhance the security interests of the United States and its allies.

“Those are the gates,” Mr. Marquez told reporters, “that the arms control proposals must come through before we consider them.”

The White House said the State Department would make more details public in coming weeks.

President Obama said in a statement that the new policy was “designed to strengthen America’s leadership in space while fostering untold rewards here on Earth.”

On the civilian use of space, the policy, which is 14 pages long, puts renewed emphasis on the commercial space industry, reflecting the administration’s desire to get the National Aeronautics and Space Administration out of the business of launching astronauts.

Listed first among the administration’s space goals is to “energize domestic industries.” That contrasts with the top goal of the 2006 Bush administration policy, to “strengthen the nation’s space leadership,” and that of the 1996 Clinton administration policy, to “enhance the knowledge of the Earth, the solar system and the universe.”

The Bush policy asserted that the government would buy commercial services “to the maximum practical extent” and refrain from federal activities that would discourage or compete with commercial options.

The Obama policy retains those provisions and, in addition, calls on federal agencies to “actively explore the use of inventive, nontraditional arrangements” like creating public-private partnerships, flying government instruments on commercial spacecraft or buying data from commercial satellite operators.

The commercial space section of the Obama policy also includes provisions for promoting American commercial space industry in foreign markets.

In contrast, the Bush administration highlighted national security concerns, like preventing unfriendly countries from obtaining advanced technologies.

Critics of that approach said the same technologies could often be bought from other countries, adding that the limitations hurt American aerospace companies without improving the nation’s security.