Presidential space policy usually emphasizes one of three preferences: active diplomacy to reduce threatening developments in space, active pursuit of military options to counter perceived threats or a policy of contingent restraint.

Presidents John F. Kennedy, Lyndon B. Johnson and Richard M. Nixon exemplified activist diplomacy, negotiating treaties that curtailed threatening developments in space. Presidents Ronald Reagan and George W. Bush pursued a different course – at least in their first terms – seeking new military options for space and rejecting diplomatic initiatives that might curtail these options. Most presidents, however, have opted for contingent restraint, and were content not to push the envelope of space or anti satellite (A-Sat) weapons as long as potential adversaries exercised similar moderation.

Active space diplomacy and the vigorous pursuit of space or A-Sat weapons are hard policy choices to execute. Multilateral treaty negotiations can be time- consuming if procedures require consensus and if countries link space negotiations with other issues.

If these hurdles can be surmounted, presidents must then confront the constitutional barrier requiring the consent of two-thirds of the U.S. Senate. The only U.S. President to pursue negotiations on A-Sat weapons was Jimmy Carter. These talks with waned as Carter focused on the completion of a strategic arms limitation treaty, and ended when the . Presidents who face many pressing issues – and surely, the next U.S. president will be among them – have shied away from new treaties governing the military use of space.

A proactive approach to space and A-Sat weapons is perhaps even more difficult to implement. President Reagan’s vision of space-based defenses that would make nuclear weapons impotent and obsolete was grounded by technical, cost and political constraints.

The United States’ closest allies, led by Great Britain, strongly resisted Reagan’s Strategic Defense Initiative, while congressional majorities imposed constraints on its pursuit as well as on A-Sat testing. During his second term, President Reagan’s commitment to space- based defenses leveraged deep cuts in nuclear offensives. As his critics foresaw, Reagan could succeed at only one, but not both, of these objectives.

President George W. Bush held out longer than President Reagan in his refusal to engage in diplomacy that might curtail freedom of action in space. But his first Secretary of Defense, Donald Rumsfeld, was unable or unwilling to implement the key recommendations of the space commission he headed before taking office, including its call for power projection capabilities in, from and through space.

Key constituencies in the Pentagon had other pressing priorities, and most Americans remain extremely leery of initiatives to “seize the high ground of space.”

Presidents who take the initiative to test and deploy space or A-Sat weapons can expect blocking action at home and abroad. Perhaps as a result, the Bush administration has been content with demonstrations of multipurpose technologies in space that could be applied to A-Sats. The Pentagon also carried out one destructive A-Sat test under the guise of negating a hazard to public safety purportedly caused by a fuel tank aboard a nonfunctional satellite.

Most presidents have been content to pursue military space policies of contingent restraint. President Dwight D. Eisenhower fixed on this objective even before the launch of Sputnik, anticipating the extraordinary value of photoreconnaissance satellites and the wisdom of allowing them safe passage. A succession of treaties, beginning with Nixon’s 1972 Anti-Ballistic Missile Treaty, followed by treaties negotiated by Presidents Reagan and George H.W. Bush, codified provisions against interfering with these satellites.

The last Democratic President, Bill Clinton, also pursued a policy of contingent restraint, deleting funds for destructive A-Sat capabilities while resisting multilateral negotiations on space or A-Sat weapons.

Which course will the next president pursue?

If past remains prologue, treaty making and the proactive pursuit of space or A-Sat weapons cannot be ruled out, but these options may well be beyond the reach of the next administration. Republican presidential candidate John McCain has not indicated interest in new diplomatic initiatives governing the military uses of space, and he has said little about space or A-Sat weapons. But Democratic majorities on Capitol Hill are likely to constrain his ability to pursue space and A-Sat weapons, if elected. Presidential candidate BarackObama has endorsed a code of conduct to reinforce norms of responsible behavior in space, but unwise actions by could constrain his freedom of action, if the Democrats regain the White House.

Michael Krepon is co-founder of the Stimson Center and the author of Better Safe than Sorry, The Ironies of Living with the Bomb ( Press, forthcoming).