Though Zalmay Khalilzad's nomination as ambassador to the United Nations is expected to sail through the Senate, some foreign policy experts aren't convinced about how effective or even how critical his new role will be.

In fact, some expectations for the foreign-born official aren't that high.

"Anything is better than (former U.S. ambassador to the U.N.) John Bolton," said Brian Katulis, a former State Department official under the Clinton administration and fellow at the Center for American Progress.

But even with Khalilzad, "the approach to the U.N. and the tensions between the Bush administration and the U.N. will still be there," Katulis said.

Khalilzad's nomination was sent by President Bush to the Senate on Monday. A spokesman with the Senate Foreign Relations Committee said the panel plans to get to the confirmation hearing as soon as possible but other issues are being dealt with first.

Observers say the biggest change between the last and next ambassador will be in style. Bolton, who left the post when his recess appointment expired in December, was known for his unfiltered criticism of the international body, his insistence on reform the and his disgust with what many say is an anti-American, anti-Israel current among member states. He has now returned to a fellowship at the American Enterprise Institute.

Brett Schaefer, a U.N. reform expert at the Heritage Foundation, said Bolton was the best chance the United States had for getting much needed reforms at the U.N. like reducing the bureaucratic glut, nepotism and general inefficiencies throughout the institution.

"Most ambassadors are not like that," said Schaefer. "It is unlikely the new ambassador will replicate John Bolton's style."

Khalilzad's style is quite different, say observers. He's been called a cultural sophisticate, a confident problem-solver and consensus builder.

In her statement announcing his nomination, Secretary of State Condoleezza Rice said Khalilzad, 55, distinguished himself in a part of the world where events and conditions on the ground were not only fluid, but dangerous.

"Zal has performed heroically and at great personal risk to help Iraqi reformers and responsible leaders build a foundation of democracy in their country," she said, adding that he did the same as the U.S. ambassador to Afghanistan following the 2002 invasion.

He has been credited with helping to broker the tough constitutional agreement in 2005 between Shiite, Sunni and secular interests in the new Iraqi parliament.

Before that he worked at the National Security Council where, Rice said, "he gained my trust and confidence, as well as that of President Bush."

But not all reviews have been rosy.

In Iraq, Khalilzad, a Sunni Muslim born in Afghanistan, was sometimes accused of taking sides with the Sunni minority's leadership. At home, critics say he is a war hawk who played a major policy role in the invasions of Afghanistan and Iraq. That status has tied him to the embattled war policies of the Bush administration and will no doubt follow him to the U.N.

"To my knowledge, he has been a faithful executor of all Bush marching orders, another Bush apparatchik," said Tony Sullivan, a Middle East expert with Near East Support Services, an international consulting firm."

Some reports have suggested that Khalilzad, who is still serving as the ambassador to Iraq, wanted out of Iraq, but was passed over for the job of Rice's deputy. John Negroponte, director of national intelligence, took over that post on Tuesday after being confirmed the evening before.

Others suggest that Khalilzad is just another casualty of Bush's Iraq policy shake-up.

"Certainly, the appointment is merely to get Zalmay Khalilzad out of Iraq with grace," said Abbas Kadhim, a professor of Islamic studies at the Naval Postgraduate School in California. "The only way to do that, without giving the impression that he was being punished, was to put him in the U.N. I think he should have been fired."

Khalilzad's temperament and style, cultivated through more than 20 years working for Republican administrations in Washington, could help ease tensions at the U.N., say supporters.

"His origins, his language skills, his cultural sensitivity have all proven to be valuable assets in Afghanistan and Iraq," said Bill Rugh, a career foreign service officer who served as ambassador to Yemen and the United Arab Emirates in the Reagan and Clinton administrations.

Rugh said Bolton has "an abrasive personal style that undermines even the reasonable positions he takes," and a "poor sense of how to deal with people so that his views are listened to and accepted."

On the other hand, Khalilzad "has a very good sense of how to deal with people of different types. He has empathy for others that Bolton lacks and he puts it to good use," Rugh said. "He can be tough and stubbornly advances basic U.S. interests, but in a way that enables him to co-opt others to the American view."

Khalilzad's Muslim identity can also play an important role, said Walid Phares, a FOX News contributor and terrorism expert with the Foundation for the Defense of Democracies.

"This would be the first time in U.S. modern history that Washington would appoint an ambassador to the Security Council whose background is Muslim," said Phares. "If he plays it well, he could be an important U.S. asset in this critical time of the War on Terror. But let's keep in mind that Mr. Khalilzad is above all an American citizen and diplomat."

That perception on the world stage could be key at this critical juncture in U.S. foreign policy.

"I think it could be helpful to have a Muslim representative, to show that the United States is multicultural, that we are not fighting Islam — and we have been unclear about that," said Rep. Donald Payne, D-N.J., who is a member of the House Foreign Affairs Committee. "I don't think it will hurt us at all."

Phares said Khalilzad's background will only go so far in determining his success at the U.N.

"At the end of the day, let's remember that governments and regimes will deal with the U.S. ambassador at the U.N. not on the ground of his or her personal background, but on the ground of who he or she represents — that is the U.S. government — and the plans underway," he said.

Others agree, saying unpopular Bush policies will be the greatest limiting factor to Khalilzad's U.N. success.

"Indeed, he is more 'Bush' than Muslim," said Sullivan. "In this case, I think the fact he is a Sunni is essentially irrelevant. It didn't help him in Baghdad, and I don't think it will in NYC"