BEIRUT >> A Saudi women’s rights activist was driving in the United Arab Emirates when she was pulled over by security officers, thrown on a plane to Saudi Arabia and jailed.

In Canada, when a Saudi student refused to stop making YouTube videos criticizing the kingdom’s rulers, two of his brothers back home were imprisoned.

So when a prominent Saudi critic, Jamal Khashoggi, disappeared after entering the Saudi consulate in Istanbul last week, it hardly surprised Saudi dissidents living abroad — until Turkish officials said they believed he had been killed.

Even for a country that has long used fear and enticements to control dissent, the prospect that the state had killed a well-known dissident writer in a foreign country represented a startling escalation.

As Crown Prince Mohammed bin Salman has pushed his vision for modernizing Saudi Arabia, he has increasingly shown little tolerance for criticism. He has jailed women’s rights activists, locked up businessmen and rival royals, and has reached across borders to keep Saudi expatriates in line, significantly raising the stakes of speaking out, even in foreign countries.

It remains unclear what happened to Khashoggi, who has not been seen since he entered the consulate last Tuesday. Turkish officials say he was killed by Saudi agents there and his body dismembered. Saudi officials deny it, saying Khashoggi left the consulate soon after he arrived.

But Saudi dissidents abroad have little doubt that their government targeted Khashoggi because of his prominence. A resident of the United States, he regularly appeared on television and contributed columns to The Washington Post.

“It’s a message, very clear, that our hands can reach you wherever you are,” said Ghanem al-Dosary, a longtime dissident in London who has a large social media following.

If Saudi agents are found to have killed Khashoggi, the reverberations could sabotage Saudi Arabia’s international relations, starting with its neighbor Turkey.

On Monday, Turkey’s president, Recep Tayyip Erdogan, demanded that the Saudis prove their claim that Khashoggi, who went to the consulate to pick up documents he needed to get married, had left the consulate.

“If he left, you have to prove it with footage,” Erdogan said at a news conference in Budapest, according to the semiofficial Anadolu news agency.

Khashoggi’s death could also undermine Saudi relations with the Trump administration, which has built close ties with the Saudi leadership.

“I am concerned about it,” President Donald Trump told reporters today. “I don’t like hearing about it. Hopefully that will sort itself out. Right now nobody knows anything about it, but there’s some pretty bad stories going around. I do not like it.”

Salman, 33, the kingdom’s day-to-day ruler, has pushed to liberalize Saudi society by letting women drive, weakening the once powerful religious police and expanding entertainment opportunities by allowing concerts and movie theaters. But those reforms have come with a stronger authoritarian hand that has tried to silence critics at home and abroad.

Many Saudi dissidents living abroad have already felt government pressure.

Some have lost government scholarships. Others have been enticed to return home only to be arrested or threatened if they didn’t keep quiet. Some have had their relatives arrested or barred from traveling. A number said they now avoided other Saudis abroad for fear of spies, and didn’t travel through other Arab countries, afraid that they could be nabbed and shipped home.

“They don’t care if you are famous, if you have a big following or not,” said the Canadian dissident, Omar Abdulaziz. ” ‘If you criticize us even a little bit, we are going to go after you.’”

The dissidents represent no monolithic organized opposition but are instead a smattering of activists, writers and social media personalities of various stripes who speak out about an array of issues. They range from those calling for toppling the monarchy to those who want more freedom inside the current system.

Loujain al-Hathloul, an outspoken women’s rights activist, made her name in 2014 when she was jailed for 73 days for trying to drive her car into Saudi Arabia from the United Arab Emirates, where she was living.

The government tried many times after that to silence her, arresting or interrogating her, her friends said. But in March, cars full of security officers stopped her on the highway in the UAE, where she was studying for a master’s degree. They handcuffed her, drove her to the airport and threw her onto a private jet to Saudi Arabia, where she was jailed for a few days.

Her husband, Fahad al-Buteiri, a well-known Saudi actor and comedian, was acting in a project in Jordan. Security officers arrested him there. He was handcuffed, blindfolded and put onto a plane for Saudi Arabia, according to the couple’s friends.

“It is like you are not immune,” Manal al-Sherif, an activist and friend of the couple, said by telephone from Australia, where she now lives. “You can be arrested anywhere and deported forcefully.”

After her release, Hathloul kept a low profile, until armed security officers stormed her home in May and arrested her as part of a wave of arrests of women who had campaigned for the right to drive. Most are still detained, and it is unclear whether they have been formally charged with any crime.

Hathloul’s marriage ended, and Butairi deleted his Twitter account, where his bio had declared him her proud husband. In July, she turned 29 in prison.

“They wanted to break her because she is a very strong woman,” Sherif said.

The Saudi government did not respond to a request for comment about its efforts to silence dissidents abroad.

But in an interview with Bloomberg last week, Salman said that some of the women arrested had been leaking information about the kingdom to the intelligence agencies of Qatar and Iran, both considered enemies of the kingdom.

He said that change in Saudi Arabia would not come without “a price,” just as ending slavery in the U.S. did not come with a violent civil war.

“Here we are trying to get rid of extremism and terrorism without civil war, without stopping the country from growing, with continuous progress in all elements,” he said. “So if there is a small price in that area, it’s better than paying a big debt to do that move.” He added: “We’re trying to be sure that no one is harmed as much as we can.”

The kingdom wielded different techniques against Abdulaziz, the dissident in Canada. After he started criticizing the kingdom’s leaders on social media as a university student, his government scholarship was canceled, he said. He was told to return to the kingdom to sort out the problem, but he applied for political asylum instead, getting it in 2014.

Since then, he has built a large audience for YouTube videos in which he makes fun of the kingdom’s leadership and criticizes its human rights record.

Representatives of the Saudi government have tried to get him to shut down his videos and return to the kingdom, he said, but when he refused, two of his brothers and a number of his friends in Saudi Arabia were arrested.

In August, researchers at Citizen Lab at the University of Toronto concluded that hackers working for Saudi Arabia had infiltrated his cellphone using software purchased from an Israeli company.

A report by Citizen Lab said the hackers would have had access to his “contacts private family photos, text messages and live voice calls from popular mobile messaging apps.” They also could have activated his camera and microphone to intercept conversations and other activities.

Abdulaziz, 27, was surprised at how far the government was going to silence him.

“Yes, I was criticizing the regime,” he said. “We were looking for freedom of speech, we were looking for human rights. But reaching out to the families of dissidents, hacking their phones, kidnapping journalists — this is crazy.”

“I am just a guy with a Twitter account and a YouTube channel,” he added. “So why is MBS, one of the most powerful men in the world, scared of me?”

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