During the U.S. presidential campaign, challenger Mitt Romney famously accused President Obama of having "thrown allies like Israel under the bus." It was an odd characterization of a policy that saw Obama make a brief, abandoned effort to limit settlement expansion, no serious attempt to stop the Jim Crow-like separate-and-unequal treatment of Palestinians in Israeli-controlled parts of the West Bank, and a determined push to ensure that the International Criminal Court won't get jurisdiction over war crimes in Palestinian territory.

But plenty of governments deserve, if not being directed to the bus, at least being shown the door when it comes to unconditional U.S. support. So-called realists will offer the usual rationalizations for ignoring that prescription. Their view of the national interest, however, is outdated in a world where modern communications make it easy for people to coalesce around grievances and perilous for governments to ignore them. The Arab Spring showed nothing if not the folly of relying on strongmen to bring stability.

In this new world, standing up for human rights reflects not only America's values but also its interests. It should be at the heart of U.S. policy, not an option of convenience. If Obama wants to bolster his legacy in his second term, he can and should get tough on some of the United States' most unsavory friends and allies. Here is a good start:

Afghanistan: As the Pentagon bows out, it is counting on Afghan President Hamid Karzai to see through the planned 2014 transition. But the Obama administration hasn't used its considerable leverage to dissuade Karzai from undermining women's rights, appointing an alleged torturer as intelligence chief, tolerating rampant corruption, and blocking efforts to hold accountable his warlord allies.

Uzbekistan: During the 2005 uprising in the town of Andijan, President Islam Karimov ordered troops to surround the demonstrators and shoot everyone in sight. Hundreds were slaughtered. His government routinely tortures dissidents and imprisons them for 15 or 20 years. Some have even been boiled alive. Yet the Obama administration soft-pedals his brutality -- and waived restrictions on selling him military equipment -- because Uzbekistan provides an alternative to Pakistan for resupplying the troops in Afghanistan. Especially as this rationale disappears, the Faustian bargain should end.

Cambodia: In 28 years as prime minister, Hun Sen has presided over the killing of countless political opponents while increasing his control of the army, police, and courts. But the Obama administration has done little to discourage him from building a one-party state, such as insisting that exiled opposition leader Sam Rainsy be allowed home without fear of arrest, and has placed no conditions on increased military ties or aid. Cambodia is where Obama should demonstrate that his Asian "pivot" isn't a competition with China for the loyalty of autocrats but a vision for Asian democracy.

Rwanda: Led by President Paul Kagame, the Rwandan government has long benefited from Washington's genocide guilt (Bill Clinton's administration sat on its hands during the 1994 massacre of more than half a million people) and admiration for its progress rebuilding the country. But the Rwandan Patriotic Front, which became the national army, itself murdered tens of thousands of civilians in the 1990s; the government uses detention and violence to shut down political opposition; and the military, despite persistent government denials, has actively supported a succession of rebel groups in neighboring Democratic Republic of the Congo. At the U.S. Congress's insistence, the Obama administration has finally suspended some military aid to Rwanda, but it continues to run political interference for the government and downplay its crimes, most recently its military support for the murderous M23 rebellion in eastern Congo.

Ethiopia: Washington had a blind spot for growing repression under the late Ethiopian Prime Minister Meles Zenawi, who died in August. In return for Ethiopia's help fighting terrorism and battling al-Shabab militants in Somalia, the Obama administration muffled its criticism of the security forces' war crimes and the government's restrictions on civil society, detention of journalists, violence against demonstrators, and pursuit of development policies that penalize political opponents.

Saudi Arabia: Yes, it has lots of oil. But the Saudis, who need cash to fuel their welfare state, are going to sell it regardless of how Obama treats them. Meanwhile, the Saudi monarchy holds thousands in arbitrary detention, imposes archaic restrictions on women, suppresses most dissent, mistreats its Shiite minority, and insists that the neighboring Bahraini monarchy crush its pro-democracy movement. Obama has been silent.

Bahrain: Saudi Arabia's next-door neighbor is the most glaring exception to Obama's generally supportive posture toward Arab Spring demonstrators. The ruling Al Khalifa family uses lethal force, torture, and arbitrary detention to crush protests. Yet out of deference to Saudi sensibilities and fear of losing the U.S. Navy's 5th Fleet base, the Obama administration has allowed its security relationship with Bahrain to trump its concern for the rights of Bahrainis -- a selectivity that undermines its broader support for Arab freedom.

Mexico: The country's drug cartels have committed horrific crimes, but so have the security forces that former President Felipe Calderón sent to combat them. Obama routinely praised Calderón's "great courage" in fighting the cartels with nary a word about widespread military and police abuses. Instead, the administration has sent some $2 billion to support Mexico's counternarcotics efforts, despite ample evidence of human rights violations and security forces so corrupt that the Mexican government has turned to its navy to crack down on the cartels.