With events in Ferguson deteriorating from day to day, despite the arrival of the Missouri National Guard, some have asked what further escalation steps are possible.

As a reminder, the reason Missouri governor Jay Nixon resorted to the aid of the National Guard is due to the limitations imposed by the Posse Comitatus Act which, broadly, seeks to limit the powers of Federal government in using federal military personnel, i.e., the Armed Forces of the United States, to enforce state laws. The Act does not apply to the National Guard, nor to the US Coast Guard, although the former will likely not see much practical use in Missouri.

However, as usually happens, there are loopholes and the best place to uncover these is in a 132-page primer conveniently released by none other than the US Army back on April 21, known simply as ATP 3-39.33 "Civil Disturbances." The primer begins with the umbrella statement:

Civil unrest may range from simple, nonviolent protests that address specific issues, to events that turn into full-scale riots. Gathering in protest may be a recognized right of any person or group, regardless of where U.S. forces may be operating. In the United States, this fundamental right is protected under the Constitution of the United States...

"Protected" it may be, but as usual, the interpretation of the Constitution is in the eye of the beholder, or more appropriately, gun holder. Because shortly thereafter we further read the following:

The Constitution of the United States, laws, regulations, policies, and other legal issues limit the use of federal military personnel in domestic support operations. Any Army involvement in civil disturbance operations involves many legal issues requiring comprehensive legal reviews. However, federal forces are authorized for use in civil disturbance operations under certain circumstances.

What circumstances? For the answer we turn to section, 2-8, whose provisions may soon become applicable to Ferguson and/or other municipal regions, should the rioting in the St. Louis suburb escalate further. To wit:

The Constitution of the United States provides two exceptions for which the Posse Comitatus Act does not apply. These exceptions are based upon the inherent right of the U.S. government to ensure the preservation of public order and to carrying out governmental operations within its territorial limits by force, if necessary. These two exceptions are— Emergency authority. A sudden and unexpected civil disturbance, disaster, or calamity may seriously endanger life and property and disrupt normal governmental functions to such an extent that local authorities cannot control the situation. At such times, the federal government may use military force to prevent the loss of life or wanton destruction of property and to restore government functions and public order. In these circumstances, federal military commanders have the authority, in extraordinary emergency circumstances where prior authorization by the President is impossible and duly constituted local authorities are unable to control the situation, to engage temporarily in activities that are necessary to quell large-scale, unexpected civil disturbances (see DODD 3025.18).

A sudden and unexpected civil disturbance, disaster, or calamity may seriously endanger life and property and disrupt normal governmental functions to such an extent that local authorities cannot control the situation. At such times, the federal government may use military force to prevent the loss of life or wanton destruction of property and to restore government functions and public order. In these circumstances, federal military commanders have the authority, in extraordinary emergency circumstances where prior authorization by the President is impossible and duly constituted local authorities are unable to control the situation, (see DODD 3025.18). Protection of federal property and functions. When the need for the protection of federal property or federal functions exists, and duly constituted local authorities are unable to, or decline to provide adequate protection, federal action, including the use of military forces, is authorized. 2-9. Laws passed by the U.S. congress include four exceptions to the Posse Comitatus Act. With the first three laws discussed below (10 USC 331–333) there is a prerequisite that the President must take personal action, including the issuance of a proclamation calling upon insurgents to disperse and retire peaceably within a limited time. The four exceptions, based on law are— 10 USC 331. When a state is unable to control domestic violence and they have requested federal assistance, the use of the militia or Armed Forces is authorized.

When a state is unable to control domestic violence and they have requested federal assistance, the use of the militia or Armed Forces is authorized. 10 USC 332. When ordinary enforcement means are unworkable due to unlawful obstructions or rebellion against the authority of the United States, use of the militia or Armed Forces is authorized.

When ordinary enforcement means are unworkable due to unlawful obstructions or rebellion against the authority of the United States, use of the militia or Armed Forces is authorized. 10 USC 333. When a state cannot or will not protect the constitutional rights of the citizens, due to domestic violence or conspiracy to hinder execution of State or Federal law, the use of the militia or Armed Forces is authorized.

When a state cannot or will not protect the constitutional rights of the citizens, due to domestic violence or conspiracy to hinder execution of State or Federal law, the use of the militia or Armed Forces is authorized. House Joint Resolution 1292. This resolution directs all departments of the U.S. government, upon request of the Secret Service, to assist in carrying out its statutory duties to protect government officials and major political candidates from physical harm.

In other words, if and when the US Armed Forces decide that rioting infringes upon any of these exclusions, then the constitution no longer applies and the use of lethal force becomes a viable option against US citizens.

It gets worse, because whereas one would expect that a "Constitutional expert" such as the president, Barack Obama would be the one tasked with interpreting if and when the Constitution no longer applies, the primer is quite explicit in handing over responsibility to "federal military commanders":

... federal military commanders have the authority, in extraordinary emergency circumstances where prior authorization by the President is impossible and duly constituted local authorities are unable to control the situation, to engage temporarily in activities that are necessary to quell large-scale, unexpected civil disturbance.

So should Obama resume his vacation even as things in Missouri escalate dramatically, and be "unreachable", it may well come to pass that Obama's opinion will be irrelevant not only whether the National Guard should be unleashed in Ferguson, but whether Posse Comitatus is suddenly null and void.

The good news: the use of lethal force is not the only option the US Army would have if and when it engages with the population. US citizens may simply be herded into "temporary internment camps" for reindoctrination purposes under the supervision of PSYOP Officer (no really, they used that word), as follows from the Army's FM3-39.40 "Internment and Resettlment Operations" manual:

Internment and Resettlement (I/R) operations facilitate the ability to conduct rapid and decisive combat operations; deter, mitigate, and defeat threats to populations that may result in conflict; reverse conditions of human suffering; and build the capacity of a foreign government to effectively care for and govern its population. This includes capabilities to conduct shaping operations across the spectrum of military operations to mitigate and defeat the underlying conditions for conflict and counter the core motivations that result in support to criminal, terrorist, insurgent, and other destabilizing groups. I/R operations also include the daily incarceration of U.S. military prisoners at facilities throughout the world. An adaptive enemy will manipulate populations that are hostile to U.S. intent by instigating mass civil disobedience, directing criminal activity, masking their operations in urban and other complex terrain, maintaining an indistinguishable presence through cultural anonymity, and actively seeking the traditional sanctuary of protected areas as defined by the rules of land warfare. Such actions will facilitate the dispersal of threat forces, negate technological overmatches, and degrade targeting opportunities. Commanders will use technology and conduct police intelligence operations to influence and control populations, evacuate detainees and, conclusively, transition rehabilitative and reconciliation operations to other functional agencies. The combat identification of friend, foe, or neutral is used to differentiate combatants from noncombatants and friendly forces from threat forces.

Presenting army camps, hopefully not in a city near you:

Detainee facilities, an important planning consideration, are treated in the same basic fashion as any base camps. The same basic planning considerations are taken into account. Some detainee facilities will be subordinate to a larger base camp but they may also be at a separate location.

And:

The PSYOP officer in charge of supporting I/R operations serves as the special staff officer responsible for PSYOP. The PSYOP officer advises the military police commander on the psychological impact of military police or MI actions to prevent misunderstandings and disturbances by detainees and DCs. The supporting I/R PSYOP team has two missions that reduce the need to divert military police assets to maintain security in the I/R facility. The team— Assists the military police force in controlling detainees and DCs.

Introduces detainees or DCs to U.S. and multinational policy.

Develops PSYOP products that are designed to pacify and acclimate detainees or DCs to accept U.S. I/R facility authority and regulations.

Gains the cooperation of detainees or DCs to reduce the number of guards needed.

Identifies malcontents, trained agitators, and political leaders within the facility who may try to organize resistance or create disturbances.

Develops and executes indoctrination programs to reduce or remove antagonistic attitudes.

Identifies political activists.

Provides loudspeaker support (such as administrative announcements and facility instructions when necessary).

Helps the military police commander control detainee and DC populations during emergencies.

Plans and executes a PSYOP

In other words, if and when the time comes to "override" Posse Comitatus, random US citizens may have two options: i) end up in the US version of a Gulag or, worse, ii) be shot.