In the four months since the violent attack on peaceful protesters by Turkish bodyguards during President Recep Tayyip Erdogan’s visit to Washington, nothing has made the Turkish government own up to this outrageous assault on democratic principles on American soil. Not protests from the State Department, not bipartisan condemnations from Congress and not the indictments of Turkish security officials on criminal charges. Perhaps a threat to block certain weapon sales will be a more meaningful way to suggest there is a price to be paid for such brutality.

Turkey’s continued intransigence about the events of May 16, in which 11 people were injured in a melee outside the Turkish ambassador’s residence, prompted a Senate committee to approve a measure that would block the U.S. government from supporting the sale of weapons to security forces protecting Erdogan.

Video of the demonstration showed protesters being chased down, kicked and beaten by men who included members of Erdogan’s security detail while the Turkish president looked on complacently.

Nineteen people, including 15 identified as Turkish security officials, were indicted on felony charges, but most are believed to have left the United States and only two have been taken into custody.

The Justice Department won’t comment on whether it is seeking extradition, and the Turkish government has been uncooperative to the point of insult. That Erdogan called the indictments “a clear and scandalous expression of how justice works in America” is in keeping with the utter contempt he has displayed so brutally in his own country toward the right to dissent, a free press and an independent judiciary.

This amendment now goes to the full Senate. Congress should approve the measure, and the president should sign it.