When Honduran President Juan Orlando Hernández was re-elected in November 2017, in a vote that outside monitors described as tainted by fraud, protesters around the country took to the streets. Hernández’s first term had been marked by violent crime and corruption; many voters wanted change.

In the ensuing days, military police opened fire on the demonstrators, killing more than 30 people and wounding hundreds. Photos published in the Miami Herald showed officers shooting some protesters in the back. They also revealed something else: The troops were using U.S.-made M4 rifles, the military version of the AR-15.

The United States provides more small arms and ammunition to Central America than any other country does. The market there steadily expanded during Barack Obama’s time in office and appears set to increase under President Donald Trump as well, according to customs data collected by the United Nations Comtrade program. Though the transactions look small compared to the multibillion-dollar arms deals the United States conducts with, say, Saudi Arabia — the United States approved $2 million to $4 million in gun sales per year to Honduras between 2015 and 2017 — the impact of such sales can be substantial in a poor country with a small population and a weak or corrupt government.

Some of those guns went to authorities who turned them on innocent civilians, as the 2017 protests show. The guns seen in the photos seem to have been exported by Colt’s Manufacturing, a Connecticut-based gun-maker. The company did not return phone calls seeking comment. Other weapons ended up in the hands of criminals, through illicit deals involving corrupt army officers, according to a 2017 report by two nongovernmental groups that investigate law enforcement and corruption in Latin America.

“There’s nobody down there we could really trust not to sell them on the black market,” said Mark Ungar, a political scientist at Brooklyn College who studies arms trafficking, gangs, and corruption in Central America. “There’s no illusion of a difference between the state and organized crime” in the region.

The violence, corruption, and abuse in Central American countries tend to be the biggest factors driving migration to the United States — a phenomenon the Trump administration has dedicated itself to curbing. Since the gun sales fuel the violence and corruption, the United States has effectively undermined its own objectives by allowing the weapons deals, according to experts.

In early February, the Trump administration finalized a rule change that will make the deals even easier — ending congressional oversight of many overseas gun sales. The president is set to move the export control process from the State Department to the Commerce Department, which is charged first and foremost with increasing sales for American companies. As a result, bureaucrats will no longer have to notify Congress of many gun sales worth $1 million or more. The only thing keeping the change from coming into force is a hold placed by Democratic Senator Robert Menendez of New Jersey, and experts are not sure how long he can keep the rule from taking effect.

“The fact that the murder rate has gone up so much over the last several years should be an indicator that this is not the time to focus on the profits for gun companies, rather than the safety of the citizens of these countries,” said Representative Norma Torres of California, a native of Guatemala and the founder of the House Central America Caucus.

“Traveling to Mexico and the Northern Triangle and talking to politicians there, this is the No. 1 topic they bring to our attention,” she said, referring to Northern Triangle countries of Guatemala, Honduras, and El Salvador.

The United States is the largest supplier of guns globally, so it makes sense that it would dominate the market in its own backyard, according to the analyst Nicholas Marsh, who tracked the U.N. data for the Norwegian Initiative on Small Arms Transfers, a nongovernmental organization. Geographical proximity reduces shipping costs, making exports to neighboring countries more profitable.

But the U.S. gun export business is also deeply tied to the country’s role in regional politics. During the Cold War, the United States supplied anti-communist insurgents, governments, and their associated paramilitaries with guns, which they used to commit human rights abuses and occasionally massacres. In the service of the ongoing war on drugs, the United States has armed increasingly militarized police forces across the hemisphere. More recently, presidents of both parties have armed anti-democratic and corrupt regimes: The Obama administration approved increasing gun sales to Honduras after a 2009 coup, and the Trump administration publicly embraced the president of Guatemala and sold him weapons despite his open opposition to United Nations anti-corruption efforts.

Under the current U.S. rules, which the Trump administration is now on the verge of eliminating, a gun company seeking to sell weapons abroad must apply for an export license and provide information on the buyer. State Department officials examine the application for signs of trafficking, like unfamiliar or blacklisted customers. The department’s official guidance suggests taking into account how the arms shipment might affect a range U.S. foreign-policy aims, including counterterrorism. It also mandates consultation with embassies and law enforcement.

If the applicant wants to sell $1 million or more worth of guns (or $14 million or more worth of larger military equipment), the State Department must notify Congress. Elected officials can then delay or cancel deals. Foreign service officers also perform “end-use” checks to confirm that the person or entity receiving the weapons matches the customer on the application.

Critics in Congress and at think tanks argue that the State Department export process still allows far too many guns to be sold into areas where they might be used to harm civilians or supply criminals, including the Northern Triangle.

The enforcement guidance does not specify which human rights abuses might be disqualifying or how to weigh the likelihood of exports being used in an atrocity, according to John Lindsay-Poland, an activist with Global Exchange who is focused on U.S. arms trade policy in Mexico and Central America . The U.S. regulations for granting export licenses merely say the State Department should “take into account” risks like human rights abuses or trafficking.

One State Department veteran insisted the rules were more than just window dressing. “It certainly wasn’t the case that these transactions were being licensed and approved willy-nilly,” said Ed Peartree, who worked as the department’s director for defense trade controls policy from 2013 to 2017.

Peartree said that under his watch, license applications were routinely denied, the size of exports reduced, and extensive conditions imposed on the end use of firearms. For all the legitimate concern about corruption, Peartree said he had seen few documented instances in which U.S. arms legally exported to police or military forces were used by Mexican or Central American criminal organizations.

The Colt booth displays M4 rifles during the National Shooting Sports Foundation’s Shooting, Hunting, Outdoor Trade Show in Las Vegas, Nevada, on January. 19, 2016.

Even so, Central America “can be a very dodgy environment to sell any firearms into,” with monitoring efforts requiring the cooperation of the host governments, he said. “There has always been the realization that we don’t know what we don’t know” about what happens to U.S. weapons after they are shipped.

Christina Arabia, who tracks small arms exports for the Center for International Policy, a Washington-based think tank, points out that the monitoring program Peartree describes is limited in scope. According to annual reports, only about 1 percent of weapon exports receive an additional check to determine whether the end user is indeed the entity who applied to buy the goods in the first place. The checks don’t examine whether purchasers may have committed human rights abuses. Even given these limitations, a quarter of all exports investigated each year around the world are found to have violated U.S. policy.

A February 2019 report by the State Department’s Office of Inspector General found that staffers often don’t follow existing rules. Auditors reviewed 21 applications to export weapons between December 2017 and August 2018. Though information was missing from 20 applications, and auditors said five were so incomplete they should have been returned, all but one were approved. The State Department failed to alert Congress as required in 17 out of the 21 cases. The auditors also found that the State Department does not have a standard training for officers who conduct end-use checks.

But the report did not lead to a tightening of oversight. On Feb. 4, officials from the State and Commerce departments briefed members of Congress on Trump’s change, which is set to weaken existing export supervision. Thirty days later, the State Department was supposed to cede to the Commerce Department responsibility for reviewing applications to export all firearms chambered to fire rounds of .50 caliber and smaller, except for machine guns, though for now Menendez has placed a hold on final implementation of the rule.

As a result, license application reviewers will no longer have to notify Congress of most large gun sales. The people with ultimate say over the exports will have less experience than their counterparts in the State Department typically had. Perhaps most importantly, the Commerce Department has a mandate to increase the business of U.S. companies above humanitarian concerns.

According to a report released by the U.S. Government Accountability Office last week, the State Department has conducted hundreds of checks each year since 2013 into how exported firearms end up being used. Forty percent of those checks were conducted in the Western Hemisphere, more than any other part of the world. But the Commerce Department has neither staffers in the region who specialize in carrying out such checks nor plans to hire any.

Immediately after Congress received its briefing on the final change, two Democratic representatives — Torres and Eliot Engel of New York — announced plans to introduce legislation that would reverse the policy. Menendez, along with a group of co-sponsors, introduced a similar bill in the Senate.

The gun industry, meanwhile, has been preparing for months. The trade magazine The Shooting Wire published an article last June encouraging gun businesses to take advantage of the looser rules, noting that they will no longer have to deal with congressional notifications and won’t have to necessarily disclose how many weapons they ship to repeat customers. “[T]here will no longer be a U.S. regulatory disincentive to accepting multi-million-dollar blanket purchase orders,” the magazine noted.

When the Obama administration considered making a similar change in 2009, officials arranged briefings with experts from a number of think tanks focused on arms control.

Central American migrants — mostly Hondurans — board a truck headed to Irapuato in central Mexico on their trek to seek asylum in the United States on November 11, 2018.

Among the participants was Colby Goodman, a longtime expert on firearms trade policy who has worked for Amnesty International and the United Nations. Goodman said officials at the White House told him they believed that “the export control system as a whole was too complicated and was hurting defense industry sales at a time of recession.” He said the officials explained to him that it didn’t make sense to subject the export of bolts and screws to the same level of scrutiny as fighter jets. But Goodman was troubled to find that the Obama administration wanted to encourage firearm sales as well, not just hardware components.

Obama’s State Department abandoned the idea in the wake of the Sandy Hook Elementary School shooting in December 2012.

Trump officials did not reach out to arms trade experts to discuss the rule change. Jeff Abramson, the founder of the Forum on the Arms Trade, had to demand a meeting. “[The Trump administration is] interested in more and more sales and [has] expressed no concern about human rights,” he said. Peartree, who no longer works in government, has a similar impression of Trump officials’ attitude toward human rights and weapons trafficking.

A State Department spokesman said in an emailed statement: “It is important to note that regardless of which Department controls the export, all items will remain subject to export licensing requirements, interagency review, and monitoring of commercial entities involved in export and sales. A U.S. Government authorization will be required for all exports of these firearms.” The Commerce Department responded to a request for comment with an email linking to an FAQ.