Journal Article - National Defense Magazine

War on Terrorism Will Compel Revisions to Posse Comitatus

The war on terrorism has made the U.S. armed forces active participants in homeland defense and, in the process, has prompted changes in the responsibilities and mission scope of the Defense Department.

The most transparent of these changes has been the establishment of the U.S. Northern Command (NORTHCOM), a new unified combatant command that became NORTHCOM covers the geographic scope of the United States, Canada, Mexico, portions of the Caribbean and the U.S. coastal waters out to 500 nautical miles. Its stated goal is to provide support to civilian authorities in the event of a catastrophe and to deter, prevent and defeat any external threats against the United States.

In the process of standing up NORTHCOM, the Defense Department has had to address several operational issues involved with coordinating a new unified combatant command within the United States. How NORTHCOM will work with local and state first responders in the event of a domestic terrorist attack is perhaps chief among them.

The Department of Defense, now consumed by a potential war with Iraq and its commitments around the globe, has provided many details in this regard. However, the question of the scope of the military’s legal authority when acting within the United States raises significant concerns. The concept of an active standing army, whatever its contours, is unique—both as a matter of practice and law—in American history.

Posse Comitatus means “power of the county.” Its origins can be traced to the< election of 1876, when U.S. troops were ordered to police polling places in the South during Reconstruction.

Determined to prevent a recurrence, Congress passed the Posse Comitatus Act in 1878. It restricts the armed forces from acting “as a posse comitatus or otherwise to execute the laws,” except “in cases and under circumstances expressly authorized by the Constitution or Act of Congress.”

Lawmakers considered the act a success on two fronts: removing military enforcement of civilian law—precisely at times when it may be most threatened—helps guarantee individual rights and liberties while quelling long-standing citizen fears of standing armies.

This is not to suggest that the act is absolute. Constitutional authority gives the president and Congress the right to suspend Posse Comitatus during emergencies. Similarly, statutory exemptions, such as those encompassed by the Stafford Act 42 U.S.C §5122 and the Insurrection Act 10 U.S.C. § 331-333, permit active military law enforcement in situations that include, but are not limited to, threats of domestic insurrection and weapons of mass destruction.

A broad interpretation of these and other statutes authorized the use of military assets in anti-narcotic and border control operations beginning in the 1980s.

Supporting Role

Assuming that the military forces serve a supporting and supplementary role, working in conjunction with law enforcement authorities, prohibitions against military involvement in anti-terror operations are generally moot—or even irrelevant.

The military services can freely participate in domestic operations with no legal consequences. In fact, following progressively sophisticated terrorism—highlighted by the 1993 World Trade Center bombing and the 1995 Oklahoma City bombing—the armed forces increasingly supplement and assist local and federal law enforcement agencies in the operational, logistical, and technical aspects of anti-terrorism.

The military’s anti-terror responsibilities during so-called “special security events” provide the best example of this role. It has become commonplace for the armed forces to help secure high-profile targets from terrorist attacks, such as the Super Bowl and presidential inaugurals.

Arguably, few question the military services’ unique abilities or importance at these venues, especially when considering the range of threats that terrorists pose when targets are not only high-value, but also geographically concentrated. Because military troops (including the National Guard) always serve a “secondary” role in these limited deployments, neither replacing local police nor enforcing civil laws, such activities are within the limits of Posse Comitatus.

Even the secretary of defense himself reminded the public of this ideal when he told Pentagon reporters that the presence of troops at the 2002 Olympics in Utah “... was done in coordination [with state and local authorities], in a supporting role.”

What had been an infrequent use of the armed forces in anti-terror activities before September 11 yielded to an expanded and obligatory role after the attacks.

No federal, state, or local law enforcement entities possessed the resources or capabilities to respond to the three massive crime scenes—let alone provide the required nationwide security in the days and weeks following the attacks. Their scope and sophistication was simply too much for any entity except the Defense Department. Almost immediately, the Air Force deployed combat air patrols to secure domestic airspace, troops took positions at passenger airports and Navy vessels patrolled ports and harbors.

It is in this context that the military’s post-September 11 homeland security initiatives must be analyzed vis-á-vis Posse Comitatus.

First, the military supplemented, and never replaced, civilian authorities. The Department of Defense provided assets, personnel and expertise to first responders—under an operational and collective rubric of cooperation. The fact that the military services did not assume unilateral control of security, rescue and recovery operations showed the continued relevance of the Posse Comitatus Act, even after 123 years.

Second, and perhaps ironically, even if the military were in violation of Posse Comitatus, the unprecedented crisis created by September 11 invoked de facto the handful of statutory exemptions that authorize military involvement during emergencies.

Further, the likelihood of future terrorist acts comparable to those of September 11 suggests that military participation in national domestic security is here to stay. It would not be unreasonable to assume that there might be limited situations, such as an attack with weapons of mass destruction, when the military would need to expand its role from mere support to active deployment.            

Indeed, public statements about NORTHCOM—that it would “deter, prevent and defeat” any external threats—are sufficiently broad to suggest that the Defense Department likely envisions such a role. This reality necessitates a reexamination of legislation that precludes, prohibits or complicates the military’s ability to defend the homeland, prosecute those responsible and restore order.

Force Readiness

The need to deal with growing domestic terrorist threats, therefore, raise some tough questions. For the armed forces to contribute effectively to homeland defense, their acute reflexes and readiness must be unimpaired.

Yet, even in wartime, the United States has always remained under civilian     governance. The Constitution and the American culture will not—and must not permit—the militarization of our government and society.

How then to respond? In order for the military to address its new homeland
security responsibilities and prepare for major contingencies, it would be
reasonable to modify Posse Comitatus.

Doing so will give the armed forces the authority and legitimacy they need, when they need it most, and establish mechanisms by which civilian officials can continue to control the forces needed for the national defense. It makes no sense to rely on statutory exemptions to Posse Comitatus when it is possible and perhaps necessary to modify the act itself.

Trying to work around the exceptions will provide no guidance to the military, nor will it satisfy public and congressional concerns—namely that the Defense Department has considered its procedures, responsibilities and limitations during domestic deployments.

Any modifications to Posse Comitatus, and therefore to the increased use of the armed forces in civilian affairs, would need to proscribe three distinct issues.

First, legal modifications would need to ensure that any deployment of military force would be the exception, and not the norm. Because NORTHCOM’s mission is so vague, a relatively high legal threshold should be in place before deployment.

Second, once deployed, the nature of its activities (with required training and
exercises) need to be delineated. The military services, unlike the police, are not trained in arrest or limited use of force. Finally, and most significantly, the law should ensure that there is a mechanism to get the genie back in the bottle. The burden should be on the Executive Branch that after a certain number of days, or only after congressional approval, could a mission continue. In this way, deployment would also be legally curtailed.

Through these mechanisms, the law would be consistent with what we might
envision as an operational worst-case scenario. Instead of finding loopholes to legal parameters, or ignoring them altogether, decision-makers need to begin to talk honestly, and publicly, about what might be in store, and ensure that the law both assists and limits military activity.


For more information on this publication: Belfer Communications Office
For Academic Citation: Kayyem, Juliette and Steven E. Roberts. War on Terrorism Will Compel Revisions to Posse Comitatus.” National Defense Magazine, () .

The Author

Juliette Kayyem Headshot