WHEN THE Obama administration resumed military sales to the Persian Gulf nation of Bahrain in 2012, it explained the decision as an effort to bolster moderate elements in the monarchy, whose Sunni ruling family has resisted demands for greater democracy from the mostly Shiite population. In particular, the aim was to strengthen Crown Prince Salman bin Hamad al-Khalifa, who was visiting Washington at the time and who had led an abortive effort to negotiate a settlement with opposition leaders.

Three months later, it’s worth asking whether the concession to a regime that has been a close U.S. ally paid off. Unfortunately, the answer is a resounding “no.” Bahrain remains locked in a standoff between a largely intransigent government and a slowly radicalizing opposition — and the regime has failed to fulfill its repeated pledges to end repression of peaceful dissent and undertake meaningful reforms.

As Assistant Secretary of State Michael Posner reported in testimony to Congress’s Tom Lantos Human Rights Commission last week, the Bahraini government has continued to prosecute 20 leading political activists; “despite assurances to the contrary,” it obtained the conviction of nine medical professionals who treated opposition activists during demonstrations last year. The country’s best-known human rights activist, Nabeel Rajab, is serving prison time for a tweet that called for the resignation of the hard-line prime minister.

Security forces continue to employ harsh tactics to put down demonstrations in Shiite villages, including what a new report by Physicians for Human Rights calls the “indiscriminate use of tear gas as a weapon.” It said police regularly fire tear gas canisters “directly at civilians or into their cars, houses or other closed spaces” in an effort “not just to disperse crowds but to harm, harass, and intimidate the largely Shia neighborhoods that are home to many protesters.”

Bahrain’s repression doesn’t approach the murderous violence used by the Syrian regime of Bashar al-Assad against its opponents. But many in the Middle East understandably wonder why the United States demands the removal of Mr. Assad, an ally of Iran whose Alawite sect is close to Shiism, while continuing to back a Sunni regime that represses its Shiite opposition. The administration’s answer is that it is not, like Bahrain’s neighbor Saudi Arabia, pursuing a sectarian agenda, but attempting to steer its ally toward peaceful reform.

Yet U.S. policy, with its focus on encouraging moderates such as the crown prince, is clearly not working. What’s needed is not just support for Bahrain’s reformers but greater pressure on its hard-liners — especially those who are complicit in torture and other illegal acts. In testimony before the Tom Lantos commission, Tom Malinowski of Human Rights Watch proposed that officials and security force members linked to human rights crimes be denied U.S. visas and access to the U.S. banking system. Since Bahrain regularly denies visas to critical U.S. journalists and human rights activists, it should have no cause for complaint if those who are sustaining its repression are similarly sanctioned.