* UN's Ban pursues quiet diplomacy with China
* Dissident urges Ban to speak out on jailed Liu
* Ban willing to stand up to Russia on Syria
* Analyst: Ban takes right approach on China
* Russia, China seen capable of paralyzing UN
By Louis Charbonneau
UNITED NATIONS, Oct 12 (Reuters) - Over the past six years U.N. Secretary-General Ban Ki-moon has undergone a metamorphosis from a soft-spoken diplomat cautiously juggling conflicting demands from big powers into an outspoken defender of human rights in Syria, Iran and elsewhere.
But his scathing public reprimands of those he considers rights abusers have yet to fall on China, where U.N. officials say he prefers to use "quiet diplomacy." It is an approach that some analysts support but frustrates rights advocates.
Secure in his second and final five-year-term, Ban has become more openly forceful, using the bully pulpit to condemn Syrian President Bashar al-Assad's onslaught against an increasingly militarized opposition and repeatedly calling for "political transition" - a polite way of saying Assad must go.
His harsh words about Assad and other autocratic leaders in the Middle East and North Africa since the Arab Spring began last year have irked Security Council veto powers Russia and China, who have rebuked Ban and Western powers for what they say is meddling in the internal affairs of sovereign states.
Ban, 68, has unquestionably aligned himself with the United States, European Union and Western countries when it comes to issues like human rights and freedom of expression. Nor did his unwavering support for military interventions in Libya and Ivory Coast or his defense of the concept of the "responsibility to protect" civilians last year endear him to Moscow and Beijing.
He has also been publicly reprimanded by Iran for castigating the Islamic Republic over its human rights record.
Ban's sharp words have not been one-sided. He has excoriated Israel for continuing to build settlements on Palestinian territory and repeatedly urged Israel, the United States and Iran to avoid "inflammatory" rhetoric and "shrill war-talk" in the escalating standoff over Tehran's nuclear ambitions.
This, analysts and rights advocates say, stands in sharp contrast to his early years after taking up the job in 2007 when he appeared more timid and less willing to take strong stands. He was often compared unfavorably with his predecessor Kofi Annan, who ran afoul of the United States by declaring the 2003 invasion of Iraq "illegal."
U.N. spokesman Martin Nesirky said Ban was now "ever more determined to hold world leaders accountable, from climate change to Syria and from poverty to women's empowerment."
But the readiness of the U.N. chief, who will remain in his post through 2016, to cross major diplomatic powers has its limits, as shown by his unwillingness to date to publicly congratulate jailed Chinese dissident Liu Xiaobo for winning the Nobel Peace Prize in 2010 or call for his release.
Ban could face a similar dilemma with the Kremlin if the Nobel committee awards the 2012 peace prize to Russian dissidents later on Friday.
DISSIDENT APPEALS TO BAN ON LIU
Chinese dissident Hu Jia, a well-known dissident under house arrest, said it was unfortunate Ban had not spoken out for Liu and about human rights in China.
"Being a South Korean, whose former president Kim Dae-jung himself won the Nobel Peace Prize, he should be well aware of how hard it is to be a human rights defender," Hu told Reuters by telephone. "I'm so disappointed in Ban Ki-moon."
"I call on Ban Ki-moon to speak out on behalf of Liu Xiaobo," he added.
When Liu won the award, Ban's press office issued a cautiously worded statement saying the prize was "a recognition of the growing international consensus for improving human rights practices." The statement did not call for Liu's release or criticize Beijing for its human rights record.
That careful wording contrasted sharply with his 2008 announcement that he was "delighted" former Finnish President Martti Ahtisaari won the award, or his 2009 statement saying "I would like to wholeheartedly welcome and congratulate U.S. President Barack Obama on winning the Nobel Peace Prize."
In October 2011, Ban welcomed the decision to award the prize to "three inspirational women of uncommon courage, strength and commitment ... three remarkable leaders" - Liberian President Ellen Johnson Sirleaf, her compatriot peace activist Leymah Gbowee, and Yemeni democracy activist Tawakkol Karman.
Philippe Bolopion of the advocacy group Human Rights Watch said that China remained "a sore spot in Ban's record on rights issues."
He added that Ban could also be more forceful about Sri Lanka and the need for accountability for the tens of thousands of civilians killed in the final months of the government's 2009 campaign to destroy the Tamil Tiger rebels.
U.N. officials have repeatedly defended Ban's cautious approach to China, which was infuriated by the Nobel committee's decision to award the peace prize to Liu, saying that sometimes quiet diplomacy is more effective than the bully pulpit - especially with a country like China.
"(Ban) has repeatedly engaged Chinese leaders on human rights matters, and he will continue to do so," said Nesirky. "If he believes he can accomplish more through quiet diplomacy, he will take that approach. But he always stands by the commitment to uphold and promote human rights in every country."
Nesirky added that Ban has "a strong record of speaking out on human rights and taking them up with governments, as his remarks in places such as Iran and Myanmar show, and as he has demonstrated repeatedly in handling sensitive issues such as post-conflict accountability in Sri Lanka."
DIPLOMACY SIDELINED IN SYRIA
Behind-the-scenes diplomacy is an approach that Ban and his envoys employed effectively for years in Myanmar, also known as Burma, which Western governments say has made significant progress in implementing democratic reforms, U.N. officials say.
Nobel laureate Aung San Suu Kyi, a pro-democracy activist who spent 17 years in detention in Myanmar, is not only free but a member of parliament since April.
Richard Gowan of New York University defended Ban's approach, saying there would be little value in confronting China on Liu because of its ability to use its Security Council veto to undermine U.N. peace efforts across the world.
"Ban has risked antagonizing China over Syria, and he must also be grateful to Beijing for intervening diplomatically alongside the U.S. to prevent a war between Sudan and South Sudan earlier this year," he said.
"Entering into a dispute over Liu might complicate cooperation with the Chinese on issues which Ban has to treat as priorities," he said. "Ban is ultimately a pragmatist."
Russia's and China's determination to prevent another Libya-style intervention in Syria has left the U.N. Security Council - which unlike the secretary-general has real power and can impose sanctions or authorize military intervention - deadlocked.
That impasse, analysts and diplomats say, has left Ban with little leverage over the 19-month-long Syrian conflict which has killed some 30,000 people, according to opposition estimates.
Diplomacy has been sidelined in Syria, envoys and analysts say, as Qatar and Saudi Arabia funnel weapons to the rebels and Russia and Iran continue to arm Assad's forces. U.N.-Arab League envoy Kofi Annan quit the post in frustration in August. He was replaced by Algerian diplomat Lakhdar Brahimi.
During his first five years from 2007 through the middle of 2011, Ban had to be careful of crossing the five permanent Security Council members - known as the "P5" at the U.N. - who had the ability to prevent him from continuing in a second term.
After his unanimous re-election last year, Ban is no longer beholden to the P5 for his job and has more freedom of movement. Gowan said he has wisely surrounded himself with "U.N. veterans who understand conflict management better than he does."
"He no longer needs to worry about Russian anger now that he has his second term," Gowan said. "Nonetheless, Ban must worry that China and Russia are increasingly ready to paralyze the U.N. on big issues like Syria. If Security Council diplomacy gets even nastier, Ban cannot do much." (Additional reporting by Michelle Nichols in New York and Ben Blanchard in Beijing; Editing by Eric Walsh)