Turkish Prime Minister Recep Tayyip Erdogan, a critical U.S. ally in the Muslim world, is struggling with the crisis in Syria, which has strained his country’s fast-growing economy, swamped it with hundreds of thousands of refugees and created unusually public friction with Washington.

The urgency of Erdogan’s concerns over Syria was underscored by Saturday’s car bombings that killed 46 people in the Turkish border town of Reyhanli, where thousands of Syrian refugees have taken shelter. Erdogan’s government blamed the blasts on the government of Syrian President Bashar al-Assad — an allegation that Syrian officials quickly denied.

Erdogan, the strongest Turkish leader in generations, and President Obama agree on broad goals in Syria, Iraq and Iran, which all share borders with Turkey. They both say Assad must go, after two years of violence that has left more than 70,000 people dead.

But the two leaders, who will meet Thursday at the White House, have sharp disagreements on their approaches to Syria and other key Middle East issues, creating divisions between Obama and a man he has praised as a “bridge” between Washington and Muslim nations.

Erdogan has pressed Washington to provide military assistance to rebels trying to oust Assad, but Obama has resisted. Erdogan is expected to raise reports that Assad has used chemical weapons against the rebels to urge Obama to take a more aggressive stance.

The urgency of Erdogan’s concerns over Syria was underscored by Saturday’s car bombings that killed 46 people in the Turkish border town of Reyhanli, where thousands of Syrian refugees have taken shelter. (Stringer/EPA)

Erdogan also wants to be more involved in the Israeli-Palestinian peace process at a time when Washington prefers that he stay quiet. And U.S. officials have complained that Erdogan’s cool, even antagonistic, relations with Iraq have done little to help quell rising sectarian violence there and curb Baghdad’s ever-closer relations with Tehran.

Obama met with Erdogan in Ankara in 2009 on his first trip to the region as president, and Secretary of State John F. Kerry has made three trips to Turkey since he took office in January. That attention illustrates the importance Obama places on Erdogan, a democratically elected Muslim leader at ease in the West and the Middle East. After Saturday’s bombing, Kerry issued a statement calling Turkey a “vital interlocutor” for the United States.

Erdogan, 59, a square-shouldered scrapper who was raised in a tough neighborhood of Istanbul, has been notably vocal in his criticism of the United States and other Western allies for not sharing his tough line on Assad.

After Assad’s forces were accused this month of killing scores of people near the Syrian city of Baniyas, Erdogan exploded with fury. “If God permits, we will see this criminal, this murderer, receive his judgment in this world, and we will be grateful,” he said in widely reported remarks.

Reacting to photos of children killed in the massacre, he also criticized the international community, and implicitly the United States, for what he sees as its failure to act. “I wonder how long you will turn a blind eye to this massacre,” he said, according to the Agence France-Presse news agency. “Damn your international policies!”

Turkish officials have said they are now hosting at least 400,000 Syrian refugees, with more arriving every day. The country has lost billions in cross-border trade with Syria, and officials worry that the fighting in Syria — and incidents of spillover violence like Saturday’s car bombings — could ignite a wider regional conflict if it is not contained.

Despite those difficulties, Erdogan comes to Washington riding high from two recent successes.

In March, Erdogan scored a huge victory when Abdullah Ocalan, the jailed leader of the Kurdistan Workers’ Party, or PKK, announced that his rebels were renouncing violence after a three-decade guerrilla war that cost at least 40,000 lives.

While many are skeptical that the cease-fire will hold, the peace deal was a remarkable achievement for Erdogan that was welcomed by Washington as a victory against terrorism.

The same week, Erdogan won another unlikely coup: an apology from Israeli Prime Minister Benjamin Netanyahu for the nine lives lost when Israeli commandos raided a Turkish ship as it attempted to breach Israel’s blockade of the Gaza Strip in 2010. Netanyahu made the call to Erdogan from an Israeli airport while visiting Obama was standing by.

The deaths had been a huge thorn in relations between Turkey and Israel, which was especially troubling to Washington, which needs its democratic allies in the region to work together.

“Israel never bent down before anyone, but they did for him — at least, that is the perception among the Turkish public,” said Cengiz Candar, one of Turkey’s leading political commentators.

Expanding power

At home, Erdogan has gradually expanded his power over every aspect of government and society. While opinion polls show that his popularity is high, they also show deep skepticism about many issues, including his aggressive Syria policy and a human rights record that has been widely criticized.

Recent surveys by MetroPOLL, an Ankara firm, show that only 28 percent of Turks approve of Erdogan’s approach to Syria and that his job approval fell to 59 percent in December from 71 percent a year earlier. Ozer Sencar, the firm’s head, said the drop in popularity was largely due to Erdogan’s Syria policies.

To his supporters, Erdogan is a visionary who has inspired Turks to “think positively about tomorrow and the future,” according to Saban Disli, a senior member of parliament from Erdogan’s Justice and Development Party and close adviser to the prime minister.

In the decade since he took office, Turkey’s economic growth has averaged more than 5 percent and per-capita GDP has tripled to more than $10,000. The growth has largely been led by exports, which have increased fivefold in the past 10 years, reaching $154 billion last year. Turkey now has 43 billionaires, up from six in 2002, according to Forbes magazine.

To consolidate those gains, Erdogan talks constantly about his dreams of a “Great Turkey.” By 2023, the 100th anniversary of modern Turkey’s founding, he vows to make it one of the world’s top 10 economies — now it ranks the 17th largest, according to the Foreign Ministry. In his mind’s eye, Turkey will have a brand-new Panama Canal-style waterway, a Turkish car brand, a vastly expanded network of highways and rails, millions of new houses — and its coming-out party will be the 2020 Summer Olympics in Istanbul.

This month, the government granted a $29 billion contract to a consortium of Turkish companies to build and operate a third airport in Istanbul designed to handle 150 million passengers when it opens in about four years. The world’s current busiest airport, in Atlanta, handles about 95 million.

Perhaps most central to Erdogan’s dreams: In 2023, he hopes to celebrate his 20th year in power, thanks to changes to the constitution that he has proposed.

‘Too much time in power’

Erdogan’s dominant persona and grand plans are unnerving to his detractors, who see him as increasingly autocratic, making Turkey richer but trampling on personal freedoms and gutting the separation of mosque and state.

“He wants to mark the 100th anniversary of the republic by challenging all the foundations of the republic,” said Osman Faruk Logoglu, a former Turkish ambassador to the United States and now a member of parliament from the opposition Republican People’s Party.

Under Erdogan, more and more Turkish women wear Islamic headscarves, there is more religious programming on television and more religious education offered in schools. State-run Turkish Airlines recently banned bright-red lipstick and dyed-blonde hair for its female flight attendants, and it has banned alcohol on most domestic flights.

Erdogan’s supporters say he is creating freedom, not suppressing it, by allowing religious people to publicly express their views in a society that long shunned them.

Many Erdogan critics are reluctant to say anything negative about him publicly for fear of retribution — lost jobs or contracts, jail time, or even being sued by the prime minister. The State Department’s 2012 human rights report on Turkey notes that Erdogan won an $8,300 award from a Turkish court last year after he sued a newspaper journalist for libel for calling him “arrogant, uninformed and uninterested.”

Erdogan’s government has jailed military officers, students, lawyers and scores of journalists, more than any other nation in the world, which has brought him sharp rebukes from former secretary of state Hillary Rodham Clinton and human rights and journalism groups.

Erdogan’s government accuses journalists and others of supporting terrorism. But press advocates argue that most were arrested simply for interviewing members of the Kurdish PKK militia.

“The shadow of the prime minister has been too dark on media ownership in Turkey; all of them do business with the government, with tax credits or contracts,” said Hasan Cemal, a prominent journalist who was forced to resign in March after he wrote a column that angered Erdogan. “That’s the authoritarian aspect of the prime minister. He likes to use his power very much. So they are all afraid of him.”

Erdogan has also proposed changing the constitution to replace Turkey’s parliamentary system with one that would be headed by a president with expanded powers. Erdogan has said he would like to run in presidential elections next year; under the proposal, presidents could run for two five-year terms, potentially leaving him in power until 2024.

Opinion polls show that Turks have a strong desire for a new constitution to replace the 1982 document that was written after a military coup. But polls also show little support for Erdogan’s ideas of a dominant presidency.

“Twenty years is too much time in power,” said Selahattin Demirtas, chairman of the Peace and Democracy Party, the political affiliate of the Kurdish PKK. “We are not afraid of a Great Democratic Turkey. We do not want a Great Authoritarian Turkey.”