Rethinking Rules of Engagement for Space

As described in the Space Warfighting framework released by the U.S. Space Force in April 2025, counterspace capabilities give U.S. military commanders a suite of combat options having attributes that are very different from traditional weapons. Historically, the authority for military commanders to use space capabilities for anything other than routine operations has been held at very high levels, making space difficult to incorporate into rules of engagement (ROE), which outline a military commander’s ability to use force without specific orders. Efforts to loosen and delegate authorities to use certain counterspace capabilities—efforts reportedly already underway to some degree—should be encouraged, with the main goal to fold space into well-defined standing and mission-specific ROE. Not doing so hinders the ability of U.S. forces to protect themselves from space threats and limits the freedom of U.S. commanders to use space most effectively for joint operations.

The U.S. military defines ROE as “directives issued by competent military authority that delineate the circumstances and limitations under which U.S. forces will initiate and/or continue combat engagement with other forces encountered,” effectively providing guardrails within which military commanders can act without additional orders. ROE can be designed to provide commanders with a wide latitude of action unless later constrained by other orders or to specify actions, such as using nuclear or chemical weapons, that can only be undertaken with specific authorization by higher authorities. Typically, ROE for commanders below a joint force commander are structured to avoid the risk of unintended escalation, so that a lower-level commander is not responsible for making decisions with strategic consequences.

The most basic ROE, often called standing ROE, covers day-to-day operations and addresses the right of military commanders at all levels to take actions in self-defense of their forces. Standing ROE typically allows for the minimally required immediate action to eliminate a threat, so long as those actions conform to the law of armed conflict stipulations on necessity and proportionality. Mission-specific ROE, also called supplemental ROE, specify situations other than self-defense during which the use of force is appropriate and often provide more detailed self-defense guidance to standing ROE, such as more instructions on interactions with unfriendly civilians. Unlike supplemental ROE, which are only in effect when commanders have received authority to execute a specific mission, standing ROE are always in effect and influence the day-to-day actions of military commanders.

There are several challenges to include space in ROE. First, military use of and threats from space pose complex questions about self-defense, proportionality, and necessity. Second, military actions involving space historically carry significant risks of escalation and, as a result, the authority to use counterspace weapons has been held at very high levels. Third, only a relatively small cadre of practitioners and commanders has experience with space and counterspace weapons. Given that standing ROE remain in effect no matter the specific operational plan or order, how space fits into ROE influences a critical aspect of the day-to-day operations of military forces. How supplemental ROE proscribe the use of counterspace weapons is another matter, because mission-specific ROE can address this issue on a mission case-by-case basis, rather than apply in all circumstances, so long as authorities to use counterspace weapons are delegated to the right levels.

A key issue for standing ROE is whether and, if so, how space capabilities pose an imminent risk and, thus, would trigger a self-defense response. Though GPS jamming or spoofing complicates the ability of a commander to carry out military operations, it is perhaps debatable whether such actions pose an imminent risk to human life. An anti-satellite missile fired at a military satellite certainly poses an imminent risk, but perhaps not a risk to human life. However, a commander of space forces, including satellites, could reasonably use standing ROE to justify a defensive response to stop such an anti-satellite missile threat. Less clear would be whether a remote sensing satellite, providing information to an adversary’s kill chain used to target U.S. forces in a non-space domain, could be characterized as an imminent threat by a commander of U.S. ground, sea, or air forces.

The next question, after assessing which space-based scenarios would qualify as imminent threats, would be to determine a response that meets the necessity and proportionality requirements. To eliminate a threat posed by a satellite, one option would be to use a nonreversible counterspace weapon to destroy that satellite in space. Another effective way to eliminate this threat may be to launch a missile or direct a cyberattack at the satellite’s ground station. Though if a defensive response to protect a satellite from a threat kills one or more human lives in the process, whether such a response is proportional might be another question to consider. Yet one other way to stop a threat from space may be to use a reversible counterspace weapon, such as an electronic warfare jammer system that could disrupt the operation of the hostile satellite.

Even if these responses are deemed necessary and proportional, they may carry escalatory risks, extending a conflict beyond the geographical region in which the fighting is occurring on land, sea, or air. Like cyberspace, outer space and the capabilities operating within are supported by a network of infrastructure, like ground stations, spanning the globe. For example, actions taken by a commander in U.S. Central Command to disable or destroy a weapon or capability relying on a space component might easily involve actions within another geographical combatant command, to include U.S. Space Command. Given that space capabilities play an important role in strategic nuclear deterrence, particularly for missile early warning, there have also been long-standing concerns that using counterspace weapons carries significant risks of misinterpretation and escalation. These geographical complications and concerns about escalatory risks are likely key drivers for holding authorities to use counterspace weapons at high levels and, historically, not delegating them to lower tactical levels.

The issue of authorities’ delegation would have to be addressed before a commander, following any type of ROE, would be able to use counterspace weapons without specific higher authorization. Hypothetically, to address a threat from space, a tactical commander might have two options. One option might be a reversible counterspace weapon that could jam the hostile satellite’s command and control signal. Another option might be to use an anti-satellite missile to blow up the hostile satellite. These options may create similar outcomes (e.g., removing the threat), but the nonreversible option carries higher escalation risks. Right-sizing the envelope of independent action for lower-level commanders to avoid strategic escalatory risk, for example, led to the creation of the Incidents at Sea Agreement in 1976 between the United States and the Soviet Union. To manage escalatory risk, it might be sensible to consider authorities’ delegation for reversible counterspace actions to tactical commanders at the lowest possible level, while retaining authorities for nonreversible actions at a higher level, possibly at the joint force commander level. Some level of delegation for counterspace actions with reversible effects reportedly may have already occurred.

Subject to policy direction and authorities’ delegation by the secretary of defense, the joint force commander responsible for space operations—the commander of U.S. Space Command—should have the lead role in setting and approving space ROE. Other joint force commanders should also, however, have significant input, possibly as part of a forum led by the secretary of defense and organized around establishing space ROE. But without increased familiarity with counterspace weapons, new space ROE and delegated authorities will not necessarily maximize the warfighter’s ability to wield counterspace weapons. Because so few military decision makers and warfighters have experience with space operations and counterspace weapons, efforts to create new space ROE should be accompanied by warfighter educational efforts focused on space and counterspace tools and tactics. The Space Warfighting framework is a promising step in that direction, familiarizing warfighters in all service branches with space operations and advancing efforts to normalize space as an operational domain.

Ultimately, the military would benefit from the inclusion of space in ROE and the delegation of authorities to use counterspace weapons, particularly those with reversible effects, to lower-level commanders across the joint force. If such efforts are already underway behind closed doors, they should be encouraged and accelerated. Concurrently, Pentagon leaders should build off the Space Warfighting framework, continuing efforts to educate defense officials, commanders at all levels, and other warfighters on how space and counterspace capabilities influence and impact battlefield outcomes. Education on space and counterspace operations, coupled with ROE and delegated authorities, would allow commanders to best defend their forces against, as well as to most effectively wield, space and counterspace capabilities to protect, defend, and advance U.S. national security interests.

Clayton Swope is the deputy director of the Aerospace Security Project and a senior fellow in the Defense and Security Department at the Center for Strategic and International Studies in Washington, D.C.