Though the United States’ ruling establishment points fingers at other governments — namely the current Syrian regime — for allegedly using chemical weapons, the American military has a history of using this vicious ammunition on its own soldiers – and fifty years later, the Pentagon is reserving its right to keep the details secret.

Between 1962 and 1974, during the Vietnam War era, the Pentagon tested nerve agents like Sarin gas and Vx and bacteria like E.Coli on as many as 6,000 military personnel in “Project 112” and SHAD (Shipboard Hazard and Defense). Most of the military members exposed to the chemical and biological weapons were in the Army and Navy, and according to McClatchy D.C., “The purpose was to identify any weaknesses to U.S. ships and troops and develop a response plan for a chemical attack.”

The outlet reported this week that though news of these practices first emerged in 2000, the Pentagon released only limited data on the tests at the request of the Department of Veterans Affairs. In the years since, the VA has commissioned studies by the National Academies of Sciences, Engineering and Medicine to investigate the tests’ effects.

“While they found no significant difference in the health of veterans involved in the tests and those who were not,” McClatchy notes, “the authors acknowledged the difficulty of studying this issue.”

This is peculiar considering, as McClatchy notes, “According to DOD documents, death can occur within 10 to 15 minutes of exposure to a fatal dose of Vx.

After exposure to a sufficient amount of Sarin, symptoms include, ‘difficulty breathing, dimness of vision, confusion, drowsiness, coma, and death.’”

According to the researchers who attempted to study the effects of the tests, multiple factors made it difficult to assess the extent of the damage to the veterans’ health.

“Our task was challenging because of the passage of time since the tests, and because many of the documents related to the tests remain classified,” last year’s report said, according to McClatchy. “Our requests for declassification of additional documents were not approved.”

On Wednesday in Washington, Ken Wiseman, senior vice commander of the Virginia branch of The Veterans of Foreign Wars, stressed the importance of uncovering the truth about these tests, which remained under wraps for decades. Despite the Pentagon’s admission in 2000, the public — and the veterans exposed to the chemicals — still know very little about them.

“Veterans were exposed to some of the most extreme and hazardous agents… and they now suffer from debilitating health care conditions,” Wiseman said.

Some members of Congress have attempted to force the secretary of defense to release more information on the tests. This week, Reps. Mike Thompson, D-CA., Don Young, R-AK, and Walter Jones, R-N.C. advocated an amendment that would have forced the Pentagon to release more information. However, a House Rules committee rejected the proposal.

In the Senate, Jerry Moran, a Republican from Kansas, is still pushing for more accountability from the Pentagon.

Moran said in a statement:

“We have a duty to make certain our service members’ health is protected both in and out of service, and providing access to classified military records that may prove exposure to toxic substances is critical to veterans applying for VA benefits and service-connection.”

This is hardly the first time the U.S. government has conducted morally questionable tests on Americans — or others. Around the same time as the Vietnam War, the military used toxic Agent Orange as a weapon in Vietnam, causing birth defects and health issues in generations of Vietnamese, as well as tarnishing the health of U.S. soldiers exposed to it, from cancer to neurological diseases, like Parkinson’s disease. The military is still paying out settlements to soldiers.

The use of depleted uranium in Iraq during the Bush era, as well as in other conflicts, is also likely causing a wide range of health issues among soldiers and victims of the United States’ military incursions.

Civilians have also been subject to government tests that damage their health. The infamous Tuskegee experiments, which began in 1932 at the behest of the U.S. Department of Public Health, tricked poor black —some of whom unknowingly had syphilis — into thinking they were getting free medical care for other issues while the researchers left their condition untreated. The Washington Post has noted they were “simply being watched until they died and their bodies examined for ravages of the disease.”

In the 1940s and 1950s in Guatemala, the U.S. government, along with Johns Hopkins University, infected hundreds of unwitting civilians with syphilis and a range of other STDs for the sake of research. Johns Hopkins was hit with a billion dollar lawsuit over it, and the Department of Health and Human Services, the office of the president, and the U.S. Secretary of State were all forced to apologize.

Meanwhile, American veterans are still waiting for accountability some 50 years later.

“It’s been over 50 years since these tests were conducted and the DOD has yet to provide a complete accounting of what truly happened to our service members,” Rep. Thompson said this week. “Veterans can’t wait any longer.”

McClatchy reports that the Pentagon and VA “did not immediately respond to request for comment.”