* Rice's chances of replacing Clinton damaged by Benghazi
* Her behavior at U.N. seen as blunt, rude by some diplomats
* Supporters say has the credentials to be top U.S. diplomat
* Has had some impressive successes for U.S. at the U.N.
UNITED NATIONS/WASHINGTON, Nov 24 (Reuters) - Susan Rice has had a series of diplomatic triumphs as U.S. ambassador to the United Nations. President Barack Obama, an old friend, showed he has her back when last week he publicly challenged her Republican critics over the Benghazi controversy to "go after me" rather than her. She knew former Secretary of State Madeleine Albright from the age of 4.
And yet Rice is now fighting for her political future. Her chances of becoming the next secretary of state - replacing Hillary Clinton - have been significantly damaged.
Senior Republicans, such as Senators John McCain and Lindsey Graham, have said they will oppose her getting the job, signaling a confirmation battle if Obama decides to nominate her. Some critics in the U.S. media, such as Washington Post columnist Dana Milbank, have said she is unsuitable for the position.
The immediate source of a lot of the criticism is her appearances on Sunday morning television shows in September five days after the U.S. ambassador to Libya, Christopher Stevens, and three other Americans had been killed in Benghazi.
Her critics bitterly complain that she misled the American public by suggesting that the assault was the result of a spontaneous protest rather than an organized assault by affiliates of al Qaeda. During the U.S. presidential campaign, supporters of Republican candidate Mitt Romney seized on the issue to attack Obama.
The antipathy in Washington and elsewhere, though, is based on more than a series of TV interviews. While U.N. diplomats and U.S. officials who have dealt with Rice praise the intellect of the 48-year-old former Rhodes scholar and graduate of Stanford and Oxford, they say she has won few popularity contests during her meteoric rise.
Diplomats on the 15-nation U.N. Security Council privately complain of Rice's aggressive negotiating tactics, describing her with terms like "undiplomatic" and "sometimes rather rude." They attributed some blunt language to Rice - "this is crap," "let's kill this" or "this is bullshit."
"She's got a sort of a cowboy-ish attitude," one Western diplomat said. "She has a tendency to treat other countries as mere (U.S.) subsidiaries."
Two other diplomats - all three were male - supported this view.
"She's not easy," said David Rothkopf, the top manager and editor-at-large of Foreign Policy magazine. "I'm not sure I'd want to take her on a picnic with my family, but if the president wants her to be secretary of state, she'll work hard."
Indeed, along with a "no-nonsense" style, Rice has the most important ingredient for a successful secretary of state - a close relationship with the U.S. president, Rothkopf said.
Russian Ambassador Vitaly Churkin, himself not known for mincing words, publicly admonished Rice after she said Russian calls for an investigation into civilian deaths in Libya caused by NATO were a "bogus" ploy.
"Really this Stanford dictionary of expletives must be replaced by something more Victorian, because certainly this is not the language in which we intend to discuss matters with our partners in the Security Council," said Churkin, mocking Rice's education at Stanford.
More immediately at the United Nations, she faces criticism from human rights activists and some diplomats because of U.S. opposition to public criticism of Rwanda for its role in the worsening conflict in the Congo.
BREAKING HER SILENCE
Rice, who declined to comment for this article, broke her silence on the Benghazi controversy on Wednesday, defending her September statements about the attack.
But she did so on Thanksgiving eve when many Americans were traveling and when her comments were likely to be overshadowed by news of a ceasefire between Israel and Hamas.
"I relied solely and squarely on the information provided to me by the intelligence community," Rice told reporters at the United Nations. "I made clear that the information provided to me was preliminary and that our investigations would give us the definitive answers."
While Rice said some statements about her by McCain were "unfounded," she may have been trying to mend fences when she added: "I look forward to having the opportunity at the appropriate time to discuss all of this with him."
People who know Rice say she is finding it hard to keep up her spirits during a long autumn of criticism. "It's not easy being attacked publicly by people who have their facts wrong day after day," one U.S. official said.
Rice's defenders say that a lot of the attacks smacked of sexism as the same tough manner she can display has been seen as an asset in some legendary male American foreign affairs officials.
Rothkopf, who was an official in President Bill Clinton's administration, cited James Baker and Henry Kissinger as exemplary secretaries of state.
They were "tough infighters who broke a few eggs and made some enemies. They are admired for their toughness, and (Rice) is attacked for her abrasiveness," he said.
SOME SAY EMINENTLY QUALIFIED
Certainly, Rice has won some accolades for pushing the U.N. Security Council to adopt new Iran and North Korea sanctions, helping secure the toughest U.N. measures to date against those two countries over their nuclear programs. Rice also played a key role in negotiating last year's war resolution on Libya.
Current and former U.S. officials aligned with the Obama administration say Rice is eminently qualified for the post of secretary of state.
They say the attacks on her during the presidential campaign were part of Republican efforts to frame the Benghazi assault as a terrorist attack, possibly linked to al Qaeda, on Obama's watch.
"The president has a great record in fighting al Qaeda, so (Republicans) try to find a way of attacking his record on al Qaeda," said Richard Clarke, who was Rice's boss when she worked at the U.S. National Security Council during Bill Clinton's first term.
Rice became an official in the Clinton administration in the 1990s, at the National Security Council and State. Then, under Obama, she became the youngest woman and the first black female to become U.S. ambassador to the U.N.
She grew up close to the levers of power. She is the daughter of the late Emmett Rice, who was a Cornell University economics professor and member of the Federal Reserve Board of governors. Albright, who is a family friend, recommended Rice to become assistant secretary of state.
"We often traveled together and I took her advice very seriously," said Albright, who served as U.N. ambassador from 1993 to 1997 and secretary of state from 1997 to 2001. "I think she is one of the smartest people I know in national security issues."
While some Republicans have accused her of sacrificing U.S. interests in her effort to woo U.N. diplomats and also complain that she is too often absent during U.N. Security Council votes, neither criticism is given much credibility by other diplomats in New York.
They say Rice, whose husband and children live in Washington and who is a member of Obama's Cabinet, has an advantage as a U.N. negotiator because other nations' delegations know that when she takes a position on an issue, the president is almost certainly behind her.
A U.N. official said that when Rice took office in 2009 as Obama's U.N. envoy, she repaired much damage done to the U.S. image at the United Nations, an organization often criticized by the administration of former President George W. Bush.
"We have paid the price of stiff-arming the U.N. and spurning our international partners," Rice told an audience in 2009. Washington quickly paid up billions of dollars in dues and said it would work with the United Nations whenever possible.
In late 2009 and 2010, Rice led negotiations on a fourth U.N. sanctions resolution against Iran over a nuclear program that Tehran insists is for peaceful electricity generation but Western powers and their allies suspect is for weapons.
Britain and France, which had drafted the three previous U.N. sanctions resolutions on Iran, were reluctant to allow Rice to be the "pen holder" for a fourth, U.N. envoys said, mostly out of fear the Obama administration would offer a weak draft because of its determination to boost engagement with Tehran.
They were wrong. Rice's draft was far tougher than expected.
The Security Council passed it in June 2010 and European diplomats who worked on it acknowledge that it created one of the toughest sanctions regimes in U.N. history.
Then came the battle for control of Libya in early 2011. After weeks of discussions within the divided U.S. administration, Obama decided that Washington could support a U.N. Security Council mandate for outside military forces to use "all necessary measures" short of an occupation to protect Libyan civilians from leader Muammar Gaddafi's forces.
The British and French were dumbstruck. Their initial reaction when Rice presented U.S. demands for a Libya resolution was that it was a ploy to get the Russians to veto it.
But then they realized she was serious.
Within 36 hours of the resolution passing on March 17, 2011, "the French were bombing Gaddafi's forces as they prepared to attack Benghazi," said one senior Western diplomat involved in the negotiations. "The Americans pushed the process well beyond what we thought we could achieve in the council, and it succeeded."
Still, it is far from smooth sailing for Rice. Security Council diplomats and human rights activists have more recently criticized her over Rwanda.
Her involvement with the East African nation began in the 1990s, when she was a National Security Council official responsible for international organizations and peacekeeping.
Still reeling from its 1993 failure in Somalia, the United States under Clinton did virtually nothing to stop the Rwanda genocide in 1994.
Nearly two decades later, council diplomats and rights groups accuse Rice of protecting Rwanda and President Paul Kagame, a charge that Rice's defenders say is baseless.
U.N. experts who monitor compliance with sanctions on Congo have accused Kagame's Rwanda of supporting the M23 rebellion in eastern Congo. M23, which is suspected of mass killings, rape and other atrocities, on Tuesday captured the city of Goma.
Rwanda denies supporting M23 but council diplomats and U.N. officials say those denials are hardly credible.
In June the experts sent a report on the allegations to the Security Council's Congo sanctions committee, where council diplomats said Rice blocked its publication for weeks. U.S. officials deny blocking it, saying Washington only wanted Kigali to have a chance to respond.
"It is patently untrue that the United States blocked the Group of Experts report as evidenced by the fact that it was released," Rice's spokeswoman Erin Pelton said on Saturday.
Just on Monday, diplomats told Reuters, the U.S. delegation again insisted that Rwanda not be named in a resolution - which was passed by the council on Tuesday - criticizing M23 rebels' seizure of Goma.
Rice's defenders say she is following instructions from Washington, and the U.S. assessment is that singling out Rwanda for backing M23 would not be constructive. They also deny that she is trying to protect Rwanda or Kagame, calling instead for negotiations between Kigali and Kinshasa.
That doesn't wash with some human rights activists. "Despite its influence on Rwanda, in public the U.S. government has been inexplicably silent," said Philippe Bolopion, U.N. director for Human Rights Watch.