By Paul Shinkman

An image of a camouflaged man in Ferguson, Missouri, training a sniper rifle on a group of protesters with their hands up has forced Americans to ask themselves what kind of protection they’re willing to tolerate. The growing militarization of domestic police forces has been a concern at home for years, but has risen to the forefront of national debate this week as shocking footage emerges from Ferguson. The St. Louis suburb remains the site of clashes and heated racial tensions between protesters, angered by the shooting death of unarmed teen over the weekend, and the police forces they believe have a history of abusive practices.

At the root of the problem is a country coming home from war, forced over a decade to design and deploy a literal army of 21st-century weapons to fight insurgent masses during protracted Middle East wars. A program that first took off in the early 1990s allows the Department of Defense, yet again downsizing, to reissue billions of dollars of this equipment to domestic security forces, particularly SWAT and other elite units that have traditionally needed tactical gear for high-risk jobs.

“Have no doubt, police in the United States are militarizing, and in many communities, particularly those of color, the message is being received loud and clear: ‘You are the enemy,’” writes Tom Nolan, a 27-year veteran of the Boston Police Department and professor at SUNY Plattsburgh, in an op-ed that appeared in DefenseOne in June, more than a month before the Ferguson riots.

Police forces are increasingly turning away from developing trust – which he considers the key tool for beat cops to fight crime – and opting instead for arsenals of assault rifles, concussion grenades and the Mine Resistant Ambush Protected vehicles, or MRAPs, that have become ubiquitous to the U.S. military presence in Iraq and Afghanistan.

“Many communities now look upon police as an occupying army, their streets more reminiscent of Baghdad or Kabul than a city in America,” Nolan continued. “This besieged mentality created by the militarization of police has driven a pernicious wedge into the significant gains made under community- and problem-oriented policing initiatives dating from the late 1980s.”

A member of the St. Louis County Police Department points his weapon in the direction of a group of protesters in Ferguson, Mo. on Wednesday, Aug. 13, 2014. On Saturday, Aug. 9, 2014, a white police officer fatally shot Michael Brown, an unarmed black teenager, in the St. Louis suburb.

The 1033 Program, named for a section of the National Defense Authorization Act, has provided congressional approval for upward of $4.3 billion in military equipment to flow to police forces throughout the country, according to an analysis from Newsweek. The program was originally designed to help outgunned law enforcement officers fight the drug trade, and quickly gained popularity among police chiefs for the high fire power and low costs. Some police forces in communities such as Watertown, Connecticut, have purchased MRAPS, originally priced over $700,000 each, for as little as $2,800, according to the magazine.

The evolution of this program has prompted some in Congress to call for its repeal. Rep. Hank Johnson, D-Ga., distributed a letter to his congressional colleagues Thursday saying he plans to introduce the “Stop Militarizing Law Enforcement Act,” which would further monitor, limit or eliminate such sales.

“Americans should therefore be concerned, unless they want their main streets patrolled in ways that mirror a war zone,” he wrote with Michael Shank in an op-ed in USA Today. “We recognized that we’re not in Kansas anymore, but are MRAPs really needed in small-town America? Are improvised explosive devices, grenade attacks, mines, shelling and other war-typical attacks really happening in Roanoke Rapids, a town of 16,000 people? No.”

Johnson’s legislation would add layers of accountability over these sales and outright ban the sales of MRAPs, armored personnel carriers, drones and other aircraft, and assault weapons, according to the letter.

“Militarizing America’s main streets won’t make us any safer, just more fearful and more reticent,” he wrote.

A New York Times feature published in June documents the stockpiling of advanced military weapons by police across the country. More than 500 military grade aircraft are now owned and operated, along with 432 MRAPs, 44,900 night vision devices and 93,763 assault weapons. The number of SWAT forces themselves has also skyrocketed during this time.

And many military veterans have come out against the violence they’re seeing at home. Twitter user @AthertonKD has put together a feed of the resulting shock and surprise.