The Administration's strategy of persuasion, alongside some mildly critical rhetoric, is unlikely to achieve much, if anything, in Bahrain. Indeed, as Landler indicates below, the Crown Prince's visit may be a political sideshow --- in mid-March, his approach of engagement of some elements of the opposition to discuss reform was quashed by other members of the ruling family, and he has struggled to regain influence since then.

As the Arab Spring grinds into summer, President Obama has turned on repressive Arab governments in different ways and at different speeds. He broke quickly with Col. Muammar el-Qaddafi of Libya and more reluctantly with Hosni Mubarak of Egypt. He slapped sanctions on Bashar al-Assad of Syria and has encouraged a Saudi-led effort to ease Ali Abdullah Saleh out of Yemen.

Only in the case of Bahrain has Mr. Obama kept out the welcome mat — prodding, cajoling and exhorting members of its royal family to ease a crackdown that crushed peaceful protesters demanding democratic change. In particular, the administration has cultivated Crown Prince Salman bin Hamad bin Isa al-Khalifa, the 41-year-old heir to the throne who graduated from American University in Washington and speaks English like someone from the mid-Atlantic region.

On Thursday, Prince Salman met Vice President Joseph R. Biden Jr., completing a high-level tour that included a White House meeting Tuesday with President Obama and his national security adviser, Thomas E. Donilon. He also paid a call to Secretary of State Hillary Rodham Clinton, who said the United States supported “the kinds of important work that the crown prince has been doing in his nation.”

The prince, who is considered the most moderate member of his family, has been assigned to lead whatever dialogue there is with the opposition. But this is the same Sunni monarchy that imposed martial law to silence the demands of the mostly Shiite opposition. It also allowed the deployment of Saudi troops as part of a campaign to stop further protests, which has included widespread arrests, detentions and, most recently, the trials of 47 doctors and nurses who treated injured demonstrators.

Given Mr. Obama’s lofty rhetoric about the historic significance of the uprisings in the Arab world, why engage with a royal family that has led such a brutal crackdown?

Partly it is an acknowledgment of geopolitical reality. Bahrain’s royal family is unlikely to topple, if only because the Sunnis who rule Saudi Arabia will not tolerate their neighbor being run by a Shiite-led government. Bahrain is also home to the United States Navy’s Fifth Fleet. And it is close to Saudi Arabia, Washington’s most powerful ally in the region.

So administration officials are clinging to the hope that, perhaps against the odds, Bahrain’s leaders — or at least the crown prince — may be willing to undertake democratic changes.

“You have somebody in the crown prince who’s credible, who seems to want to do the right thing,” said one senior administration official. But, as another administration official put it, “It’s not as if we have that many choices about who to talk to about promoting a dialogue.”

Even before the uprisings, the United States looked to Prince Salman. In a diplomatic cable sent by the American Embassy in Bahrain in late 2009, and made public by WikiLeaks, he was described as “very Western in his approach” and “closely identified with the reformist camp in the royal family — particularly with respect to economic and labor reforms designed to combat corruption and modernize Bahrain’s economic base.”

But several analysts warn that even if Prince Salman is sincere, he is only one member of a family that includes hard-liners like his uncle, Prince Khalifa bin Salman al-Khalifa, the long-serving prime minister. With his mild manner and fluent English, Prince Salman may be merely the monarchy’s friendly face, skeptical analysts say.

The prince is on “a world tour to convince people that Bahrain is turning over a new leaf when in fact the hard-liners are conducting business-as-usual at home,” said Leslie Campbell, regional director for the Middle East and North Africa at the National Democratic Institute, which is active in Bahrain.

State Department officials are alarmed that in recent weeks Bahrain’s state-owned media mounted a virulent anti-American campaign against the embassy, accusing it of colluding with Shiite groups. An American diplomat involved in human rights issues recently left Bahrain after receiving threats, including from a blogger, who referred to the diplomat’s wife as being Jewish.

Despite this, Mr. Campbell supports the outreach to the prince, saying that it makes sense to strengthen the hand of someone “who is at least by inclination moderate and fair-minded.”

The administration, he said, should extract concrete pledges from the prince about how he plans to respond to protesters’ demands for a more open society. His father, King Hamad bin Isa al-Khalifa, recently lifted the state of emergency and announced that talks with the opposition would resume in July. But the Saudi troops who carried out the crackdown remain in the country, and some of the top opposition leaders are languishing in jail — a fact that Mr. Obama underscored in his recent speech on the Arab upheaval. The president pressed Prince Salman about the prisoners in their meeting, an official said, but it was unclear how he responded.

The prince did express regret about how the crackdown had tarnished Bahrain’s image, particularly since the government had worked so hard over the past decade to present Bahrain as an enlightened Persian Gulf kingdom. Hanging hopes for change on whether the royal family fears a public-relations disaster is a slender reed.

But in the end, Mr. Obama may have little choice because the alternative, said Tom Malinowski, the director of the Washington office of Human Rights Watch, is “either violent upheaval or permanent repression.”