Martial law occurs when the military or militarized law enforcement replaces civilian authorities in order to impose military rule during an emergency. Civil liberties are suspended. In the United States, a pivot point that signals martial law is the suspension of habeas corpus - the right to a hearing on whether an imprisonment is lawful. In practice, habeas corpus means a person cannot be imprisoned without legitimate charges and due process. The U.S. Constitution recognizes the suspension of habeas corpus as an identifying feature of martial law in Article I, Section 9, "The Privilege of the Writ of Habeas Corpus shall not be suspended, unless when in Cases of Rebellion or Invasion the public Safety may require it."

Obama is preparing to declare martial law in America. He may decide not to do so but it is a prepared option that requires nothing more than the say-so of one man. The necessary Executive Order has been authorized. The National Defense Resources Preparedness grants Obama power over "resources and services needed to support...plans and programs" in "the event of a potential threat to the security of the United States." The grant of authority is so complete that it includes the ability to commandeer technology, industry, and the nation's other resources down to its ""food resources, livestock resources, and the distribution of farm equipment and commercial fertilizer."

The legal framework for martial law is in place.

The signs are unmistakable. They include: Homeland Security recently purchased $1.6 billion worth of ammunition for domestic use by its 100,000+ armed enforcement agents; it also acquired thousands of military-style armored vehicles.

The clearest sign, however, is the National Defense Authorization Act - the federal legislation through which the budget and expenditures of the Department of Defense are specified each year. In 2012, Sec. 1021 of the act allowed the military to arrest and imprison an American on American soil without habeas corpus if he was deemed to have "committed a belligerent act or has directly supported such hostilities in aid of such enemy forces" (e.g. the Taliban). The 2013 act included the same provision. In short, the NDAA authorized indefinite detention without due process. The 2014 act is currently under debate. It would expand the military's power over the civilian population through Sec. 1061 which is also known as Enhancement of Capacity of the United States Government to Analyze Captured Records. It authorizes the surveillance of an individual solely on the basis that he is or has been hostile to the United States. In short, the new NDAA would authorize indefinite surveillance.

The enforcement mechanism for martial law is in place. What would it look like?

There is no need to speculate. The police response to the Boston Marathon bombings provides a glance into what Americans can expect in the event of another terrorist attack or domestic unrest. Or, rather, it provides an example of a kinder, gentler martial law than is likely to occur. It is kinder and gentler because the agents in Boston had no reason to be hostile to the civilian population; they had the specific goal of capturing a fugitive rather than the general one of policing the population; no one resisted; and, the agents could have faced consequences such as lawsuits if they had inflicted injury. Most martial law scenarios are likely to be more brutal.

On April 15, 2013, three people were killed and hundreds injured when pressure cooker bombs exploded during the Boston Marathon. Two brothers named Tamerlan and Dzhokhas Tsarnaev became suspects. Tamerlan died, Dzhokhas escaped. An unparalleled manhunt occurred on April 19.

The Boston Globe (June 8) explained why law enforcement's response was so coordinated. "The [police training] scenario had been carefully planned: A terrorist group prepared to hurt vast numbers of people around Boston would leave backpacks filled with explosives at Faneuil Hall. But two months before the training exercise was to take place, the city was hit with a real terrorist attack executed in a frighteningly similar fashion."

The mainstream media reported that "officers in body armor were going door-to-door checking if families were safe" and checking out homes to find the fugitive. (Los Angeles Times, April 19) The unreported reality was more disturbing.

Watertown, a bedroom community of Boston, was one of the areas put on "shelter-in-place" - an emergency procedure that is most often associated with chemical spills. The procedure involves people staying indoors, mostly in their homes, while the danger is handled by authorities. It is a form of martial law with law enforcement replacing the military as actors. Civil liberties are suspended, of course.

When the fugitive was spotted in Watertown, agents in riot gear descended on 20 blocks of the town, accompanied by armored personnel carriers. The civil liberties of residents were suspended by the pronouncement of one word: "manhunt." Two syllables - that's how quickly totalitarianism descends.

With dogs and without warrants, the agents went from house to house and forced people to vacate at gun point. Residents in robes were driven into the street and not allowed to turn off lights, lock doors, secure pets, or grab a cell phone. No questions were permitted. One video shows an agent violently slapping people's elbows upward to force hands behind their heads. Another shows a soldier in a tank pointing his rifle at a photographer. The following video entitled "MSNBC Host Caught Lying About Watertown Martial Law" describes typical encounters. The lies? No tanks were used, no guns were pointed at families.

In the end, Dzhokhas was apprehended only after the lock-down of Watertown ended and the agents had departed. A resident discovered Dzhokhas hiding in his backyard and reported him to the police. The agents had overlooked the fugitive's presence.

The lock-down of the Boston area is not an isolated incident. It is part of a well-funded, coordinated federal program called Operation Urban Shield. (The Boston training exercise received a $200,000 grant from Homeland Security.) The Urban Shield website states, "The overarching goals of Urban Shield include striving for the capability to present a multi-layered training exercise to enhance the skills and abilities of regional first responders, as well as those responsible for coordinating and managing large scale events." Law enforcement is being trained to impose martial law. Americans are being trained to obey without question.

People sometimes marvel over how a civilized populace like the pre-Nazi Germans were blind to the approach of totalitarianism. How could they miss the signs? Most Americans are missing the hint presented by armored personnel vehicles rolling into a peaceful community. They prefer media lies to the sight of agents aiming their guns at typical American families. That preference will also facilitate martial law.

The best way to avoid martial law in America is not to be here when it occurs.