In response, the NSSS stated that developing norms for responsible space operations will be a key component of the Pentagon strategy for achieving two of its stated goals: promoting the responsible, peaceful, and safe use of space, and preventing and deterring aggression against U.S. national security assets in space. 

Currently, the leading diplomatic effort to establish such norms is the Code of Conduct for Outer Space Activities, an effort shepherded by the European Union and being considered by a number of spacefaring nations, including the United States, whose final decision is expected soon.

However, pushback from missile defense partisans may threaten to derail that step. On February 2, a group of 37 Republican senators wrote a letter to Secretary of State Hillary ClintonHillary Diane Rodham ClintonNew FBI document confirms the Trump campaign was investigated without justification California 25 and COVID-19 The Memo: Trump tweets cross into new territory MORE expressing concerns about how such norms might impact US activities, most notably missile defense. The senators have asked Secretary Clinton to brief the relevant Senate committees and for her "personal response" to their questions.

They want to know what impact signing the Code might have on a U.S. decision to deploy missile defense interceptors in space; whether it would affect the development, test or deployment of an anti-satellite weapon; or if it would affect the possibility of putting weapons in space meant to counter anti-satellite weapons.

In fact, the voluntary Code does not mention space weapons of any kind, nor would it meaningfully limit their development. It reaffirms what is already agreed in the Outer Space Treaty; declares that subscribing states will refrain from damaging outer space objects unless for debris mitigation, self-defense, or public safety reasons (the nominal motivation of the U.S. destruction of a failed spy satellite); and will promote efforts toward “the prevention of an arms race in outer space.”

While the senators are exercising their duty and right to be asking questions, inhibiting these initial efforts to establish norms is shortsighted and counterproductive.  We should be seeking more, not less. 

Norms are a modest step in the right direction, but leave many of the serious problems of space security unaddressed. Without robust constraints on anti-satellite weapons, for example, threats to satellites will continue to proliferate and mature, requiring the United States to expend more effort securing satellites and leading to less predictability and stability in crises.

Moreover, U.S. leaders need to recognize the implications for space security of pursuing space-based missile defense. A space-based missile defense system would be enormously expensive yet provide no reliable defense, and is thus unlikely to be built. Yet the space-based interceptors could have significant capability to attack satellites, and therefore be offensive rather than defensive.

If the United States put even small numbers of test interceptors in orbit, other countries would see that as fielding space weapons. This could spur them to develop and deploy space weapons as well. The United States would be more secure in a world in which such needlessly provocative activities were explicitly limited or banned.

For this reason the United States, as the preeminent presence in space, should play an active and leading role in engaging the international community to further develop space laws and norms and to keep space free of weapons. A Code of Conduct provides a useful but preliminary standard for responsible space conduct.  It should be a first step, but not the last.

Laura Grego, a scientist in the Union of Concerned Scientists’ Global Security Program, is an expert on space security issues.