A bipartisan group of members of Congress led by Rep. Mike Honda, D-Calif., has called on Defense Secretary Ash Carter to apologize to American veterans who were used in race-based chemical weapons experiments. Their letter comes in response to a recent NPR Investigation into the tests, which were conducted during World War II.

We found that the U.S. military exposed black and Puerto Rican soldiers to mustard gas and other chemical weapons on the theory that people with dark skin could be more resistant, and that Japanese-American troops were tested as proxies for the Japanese enemy. White soldiers were also exposed in the tests. They made up scientific control groups, whose reactions were used to establish what was "normal," and compared to the others.

These tests were first written about in an academic journal article in 2008, which didn't get much attention. NPR's reporting caused the Pentagon to acknowledge the experiments for the first time.

The group of U.S. representatives — 13 Democrats and one Republican — is calling on the Pentagon to amend test subjects' official military records to reflect the experiments, which were formally declassified in 1993. Test subjects were previously sworn to secrecy under threat of dishonorable discharge and prison.

Honda is joined in sending the letter by Walter Jones, R-N.C., who sits on the House Armed Services Committee, and Jerry McNerney and Mark Takano, both California Democrats who sit on the House Veterans Affairs Committee.

"It is long past time to look these veterans in the eye," the letter states, "and finally say on behalf of the American people that what the United States government did to them was shameful and wrong, and we are sorry."

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