Cambodia’s democracy has been in increasing trouble in recent months, with Prime Minister Hun Sen dissolving the main opposition party and cracking down on independent media. Now there’s a sign that the U.S. government is paying attention.

The Treasury Department announced Tuesday that it will sanction Hing Bun Hieng, the commander of Hun Sen’s bodyguard unit, for carrying out “serious acts of human rights abuse against the people of Cambodia.” The sanctions mean that Americans are barred from doing business with Bun Hieng and that any assets he has in the United States will be frozen.

The bodyguard unit, an elite force under the military with thousands of troops, is involved in internal security matters and has been linked to numerous crackdowns on the opposition. But the sanctions announcement goes beyond Hun Sen’s recent anti-democratic moves in Cambodia. The Treasury Department’s release specifically mentions Bun Hieng and the bodyguard unit’s connection to a 1997 grenade attack on an opposition rally that killed 16 people and wounded more than 100.

The attack, still unsolved and unpunished, injured an American democracy activist, Roy Abney. The Treasury Department statement refers to him as a “U.S. citizen” who suffered shrapnel wounds. The U.S. government has so far “been reluctant to make this allegation public,” said Sebastian Strangio, a journalist who has written a book on Hun Sen. “That it is doing so now speaks to how far relations between Phnom Penh and Washington have frayed.”

But the choice of Bun Hieng is something like a warning shot, Strangio said. While Bun Hieng “occupies an important and symbolic part of Hun Sen’s personal security architecture and is alleged to have had a hand in a long list of human rights abuses,” Strangio said, he is a marginal economic and political figure whose blacklisting is unlikely to cause a rupture between Washington and Phnom Penh.

Nevertheless, Cambodia’s government was quick to criticize the sanctions. The Cambodian Defense Ministry issued a statement Wednesday saying the U.S. action was a “stupid decision that Cambodia cannot accept,” according to the Associated Press.

Hun Sen’s government is likely to cite the sanctions as further evidence of U.S. bias against his government. The United States has become somewhat of a boogeyman, analysts say, as Hun Sen stokes anti-American sentiment in Cambodia ahead of elections there on July 29.

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