Operating in the Dark: Rules of Engagement Needed for Space
By: Todd Harrison
Space has been an integral part of U.S. military power since the 1991 Gulf War. From global positioning system (GPS)–guided bombs to satellite-linked unmanned vehicles, space-based capabilities are a routine part of military operations—and a growing source of vulnerability. As antisatellite (ASAT) capabilities proliferate, the United States must prepare for a future conflict that could extend into space. A range of both kinetic and non-kinetic threats, such as jammers, lasers, and high-powered microwave weapons, could deny the United States use of its space assets either temporarily or permanently, depending on the threat.
This raises an interesting question for policymakers: Does the U.S. military need explicit rules of engagement for space? Consider three hypothetical scenarios for how a conflict could extend into space:
- A U.S. imaging satellite conducting routine reconnaissance during peacetime is temporarily blinded by a ground-based laser.
- Satellite communications links to U.S. unmanned aircraft being used for counterterrorism operations are jammed just as a high-value target enters the field of view, allowing the target to escape.
- During the early phases of a major regional conflict, a U.S. missile-warning satellite is struck by a previously undetected satellite in a crossing orbit.
How should the United States respond in each of these scenarios? A number of factors must be considered, such as: are the effects of the attack temporary or permanent; does the attack endanger U.S. personnel or ongoing combat operations; is the capability lost difficult to replace; is attribution clear or difficult to discern; are there secondary effects, such as orbital debris, that could affect other satellites; and does the attacker know if the attack was successful. Without rules for engagement, it could take days or weeks to sort through these questions and formulate an appropriate response—time that may not be available in a crisis. And perhaps more importantly, how would adversaries expect us to respond?
Publicly sharing (in whole or in part) U.S. rules for engagement in space could help deter some types of attack by making the prospect of retaliation more credible. There are few widely accepted “norms” for space operations, particularly when it comes to military uses of space, leaving ambiguity that others may seek to exploit. And as the Chinese ASAT test in 2007 proved, space is still in many respects a “wild west” frontier where each nation is making up its own rules. Though the absence of a widely accepted code of conduct in space makes it more difficult to gain consensus as to what constitutes unacceptable behavior, establishing clear rules of engagement in space—and communicating these to others—could help promote a de facto set of “norms.” Other nations know that if they fire on a U.S. warship, the ship can and will return fire. Similarly, others should know that if they attack U.S. military satellites, there will be consequences.
Rules of engagement in space should define what types of actions are considered hostile and what responses are proportionate and legitimate. They should, for example, address scenarios such as the three postulated above. The temporary blinding of a U.S. satellite in the first scenario is clearly not an acceptable action, but the response to this should be less severe than the response warranted by the physical destruction of a satellite postulated in scenario three. Rules of engagement should define the range of retaliatory measures that would be considered for different offenses, while not necessarily committing the United States to any particular course of action. Moreover, rules of engagement should note what actions in space cross the threshold of warranting a kinetic (and potentially lethal) response in other domains—e.g., attacking an adversary’s forces on earth. By spelling out these guidelines on paper and following them in practice, the United States can take a significant step toward encouraging responsible behavior and enhancing deterrence in space.