“Neither the Turks nor the Saudis are credible,” said Steven A. Cook, a senior fellow for Middle East and Africa Studies at the Council on Foreign Relations. “Both have sought to delegitimize domestic and international critics with propaganda, half-truths and outright lies.

"It is true that even liars sometime tell the truth, but because they are liars, we need to be extra careful," he added. "The Saudis have a problem because no one has seen Khashoggi in a week. If he had left the consulate, surely someone would have seen him. This raises the possibility that the Turks are telling the truth."

A prominent journalist once close to the inner circle of Saudi Arabia’s huge royal family, Khashoggi went into self-imposed exile in the U.S. after Salman replaced older cousin Prince Muhammad bin Nayef as crown prince in June 2017. In the U.S., Kashoggi became a contributor to The Washington Post.

Jamal Khashoggi speaks at an event in London Britain on Sept. 29. Middle East Monitor / Reuters

Mohammed bin Salman, 33, King Salman's son, was at first hailed internationally for efforts to reform his country's oil-dependent economy and modernize the deeply traditional society, and won much coverage in June for allowing women to drive.

But just ahead of that, the kingdom rounded up and imprisoned women's rights activists and turned Riyadh’s Ritz Carlton into a luxury prison for businessmen, royals and others who were forced to sign over some of their assets.

Vice President Mike Pence said Tuesday he was “deeply troubled” by Turkey’s suggestion that Khashoggi had been killed. “If true, this is a tragic day,” he tweeted. “The free world deserves answers.”

State Department officials have spoken with Saudi Arabia through diplomatic channels, Secretary of State Mike Pompeo said Tuesday in a statement that called on Riyadh to be “transparent.”

Turkish President Recep Tayyip Erdogan can hardly claim to be shocked by the week’s events. His spokesman last month renewed a menacing pledge to conduct “operations” against political enemies on foreign soil, including inside the United States. Turkish agents have already kidnapped several such opponents in countries including Kosovo, Moldova, Ukraine and Azerbaijan.

The case also reflects on the extent to which leaders with authoritarian leanings have been emboldened by Trump, said Cook.

“The Trump administration has de-emphasized human rights, and we do seem to be in an era where there are no norms,” he said. “That said, there have been assassinations, kidnappings and all kinds of nefarious business by countries long before Trump was elected.

“It feels like the world is more dangerous for journalists, in particular, now because the president of the United States speaks about the press in a way that is more akin to Middle Eastern authoritarians than American presidents.”

Cold weather

Turkey’s rift with Saudi Arabia widened in December when it signed a deal with Iran to break a Saudi-led economic blockade against Qatar. Riyadh, an arch-rival of Iran, accuses of Qatar of aiding regional terrorism. Ankara, which has a military base in Qatar, sent supplies during the boycott.

Turkey has also led the outcry over Trump’s decision to recognize Jerusalem as the capital of Israel, while Saudi Arabia has been cooler in its criticism as it looks instead to longer-term Mideast peace efforts by White House adviser — and Trump’s son-in-law — Jared Kushner.

But the fallout began as far back as 2013, when Egypt's democratically elected president, Mohammed Morsi, was overthrown in a military coup that the U.S. did little to oppose.

Saudi officials arrive at Saudi Arabia's consulate in Istanbul on Tuesday as demonstrators gather to protest the Khashoggi's disappearance. Bulent Kilic / AFP - Getty Images

Erdogan, a political Islamist, is a strong ally and supporter of the Muslim Brotherhood movement and believes Saudi Arabia was a key player in Morsi’s ouster.

“There has been cold weather between Turkey and Saudi Arabia for a couple of years,” said Bağcı. “Erdogan still supports the Muslim Brotherhood and Saudi Arabia and now Egypt are both against it. The relationship between Ankara and Riyadh is certainly not as close as before and this makes the Khashoggi case more complicated.”

Turkey’s economic crisis and increasing diplomatic isolation means an all-out battle with Saudi Arabia and its rich Gulf allies could be painful.

All of which will overshadow any international response to Khashoggi’s fate.

Fighting the fire

Joseph Bahout, a Carnegie Endowment for International Peace scholar on the Middle East who knew Khashoggi for 15 years through conferences and professional circles, said Erdogan will have to react strongly against Saudi Arabia.

If Turkey's president "embraces" the idea that Khashoggi has been killed by the Saudis on Turkish soil, "he will take it as a humiliation, I mean as a blow, not only because it means that Saudis can do whatever they want on Turkish soil but also because there are ties between Khashoggi and the Turkish establishment.”

Turkey’s next steps could be expelling the Saudi diplomatic mission, calling back the Turkish ambassador, cutting diplomatic ties and eventually taking Riyadh to the International Criminal Court.

However, Erdogan, who has declared an “economic war” against the U.S. and is locked in a diplomatic dispute over the detention without trial of a North Carolina priest, will not be able to rely on Washington for help.

Deeply troubled to hear reports about Saudi Arabian journalist Jamal Khashoggi. If true, this is a tragic day. Violence against journalists across the globe is a threat to freedom of the press & human rights. The free world deserves answers. — Vice President Mike Pence (@VP) October 8, 2018

“The Turks have used up every ounce of goodwill they had in D.C. and then some,” said Cook. “For the Trump administration, Saudi Arabia is of utmost importance even as the Saudis just do whatever they want with little regard for Washington’s views.”

If Khashoggi has come to harm, it would “absolutely destroy the goodwill generated by recent relations with the U.S.,” said Jonathan Schanzer, senior vice president at the hawkish Foundation for Defense of Democracies think tank.

Bahout said Ankara could strengthen its support for Qatar or increase its involvement in Yemen, where Saudi Arabia is fighting against a Shiite group in what is seen as a proxy war against Iran.

“It won’t stay at all a Saudi-Turkish issue. It will very quickly engulf other actors,” Bahout said. “It will have a huge effect. This is why I think the Americans should be ... working on trying to find a solution.”

Alastair Jamieson reported from London, and Kristina Jovanovski and Aziz Akyavas from Istanbul.