Updated

What do Cuba, China, Saudi Arabia and the United States have in common? On May 12, the United Nations General Assembly votes on whether those nations and 15 others get seats on the U.N. Human Rights Council.

The 47-member council was shunned by President Bush because it includes some of the world's most repressive regimes and brutal violators of the very rights it is meant to protect.

But after three years of American absence, President Obama now hopes to confront those regimes -- using a seat on the council to press for human rights investigations in hotspots like Darfur and the Democratic Republic of Congo.

Human rights organizations have hailed the U.S. decision to rejoin the council, but critics say America can do little in the U.N. venue and should not join at all.

"U.S. membership, or the membership of any other single state, is not going to make the council effective," said Brett Schaefer, a fellow at the conservative Heritage Foundation.

Schaefer and many rights watchdogs fault the council for doing work that has often been detrimental to human rights around the world. It has passed resolutions banning free speech, spent most of its energy producing condemnations of Israel, and eliminated human rights oversight in Congo, Cuba, Belarus and Darfur.

"It's been an incredible disappointment in its first three years," said Schaefer. "The Human Rights Council was established in 2006 because its predecessor was deemed to be ineffective and an embarrassment," he said, arguing that the council has repeated every mistake of the much-derided Human Rights Commission, which met from 1946-2006.

Yet some human rights groups see the American absence from the council as harmful and think that its many systemic problems can be addressed only if the U.S. is a member.

Paula Schriefer, director of advocacy for Freedom House, hopes to see incremental changes from the Geneva-based council with help from the U.S.

"It's all of the behind-the-scenes work that will determine whether the council can be turned around," she said, adding that the U.S. must lobby its allies on the council to stop defending despots and help back strong resolutions condemning rights violations.

Schriefer said the U.S.'s influence will be much more important than its vote, because it will effectively be replacing Canada, which had a sterling record during its three-year term.

But Canada was outnumbered. Only 22 of the 47 members of the council are considered free nations by Freedom House, and eight of Tuesday's 19 candidates are considered entirely unqualified to judge and promote human rights, the group found.

Those eight -- Azerbaijan, Bangladesh, Cameroon, China, Cuba, Djibouti, Russia and Saudi Arabia -- are currently on the council, and at least six are essentially guaranteed to be re-elected to it.

The questionable makeup of the council is all the more reason for the U.S. to push hard to improve its behavior, some advocates say -- though even U.S. pressure is unlikely to produce concrete results from within the U.N.

"Nothing will stop America every day, every week, every month from introducing resolutions on Zimbabwe, on Cuba, on China," said Hillel Neuer, director of U.N. Watch, which monitors the U.N. from Geneva.

"They will not be adopted -- they will fail -- but they will put a spotlight on the abusers."

Critics including Schaefer have said that the U.S. can shine that spotlight from outside the controversial council, and that it should not join until there are "serious and strong membership criteria."

Those criteria would be up for rejiggering in 2011 when the U.N. conducts a 5-year review of the council, and Schaefer thinks the U.S. could have used its absence on the council as leverage -- agreeing to join the body only once it reforms itself.

But with human rights crises continuing to erupt around the world, some experts say the U.S. needs to engage at the U.N. right now and cannot wait for a review in two years.

"Ironically, it's an engagement that requires confrontation," Neuer said. "This engagement is not to smile and make nice -- it's to get in there and to slam the Chinese for their egregious violations.

"If America fails to do that, they will have failed us all."