MOSCOW (NYTIMES) - Even as President Vladimir Putin tightened his grip on Russian society over the past 22 years, small pockets of independent information and political expression remained online.

Any remnants of that are now gone.

As Mr Putin waged war on Ukraine, a digital barricade went up between Russia and the world. Both Russian authorities and multinational Internet companies built the wall with breathtaking speed. And the moves have ruptured an open Internet that was once seen as helping to integrate Russia into the global community.

TikTok and Netflix are suspending their services in the country. Facebook has been blocked. Twitter has been partially blocked and YouTube's future is in doubt. Apple, Samsung, Microsoft, Oracle, Cisco and others have pulled back or withdrawn entirely from Russia. Even online video games like Minecraft are no longer available.

The actions have turned Russia into a walled-off digital state akin to China and Iran, which tightly control the Internet and censor foreign websites and dissent. China's Internet and the Western Internet have become almost completely separate over the years, with few overlapping services and little direct communication. In Iran, authorities have used Internet blackouts during protests.

Russia's cleaving off is a defeat for the once-held Western belief that the Internet is a tool for democracy that would lead authoritarian countries to open.

"The vision of a free and open Internet that runs all over the world doesn't really exist anymore," said Mr Brian Fishman, a senior fellow at the New America think tank and former director of counterterrorism policy at Facebook. "Now the Internet is lumpy. It has choke points."

The Internet is only one piece of Russia's growing isolation since it invaded Ukraine on Feb 24. The country has been largely cut off from the world's financial system, foreign airlines are not flying in Russian airspace, and global access to its oil and natural gas reserves are in question.

But the digital cutoffs stand out as the culmination of attempts by Russian authorities to tame what was once an open and freewheeling Internet. For years, officials stiffened a censorship campaign at home and tried to move toward what is known as a "sovereign Internet". The war led multinational companies to take the final steps.

While Russia is paying a stiff economic cost for being cut off, the digital isolationism also serves Mr Putin's interests. It allows him to clamp down further on dissent and information that does not follow the government line. Under a censorship law passed last week, journalists, website operators and others risk 15 years in prison for publishing "misinformation" about the war on Ukraine.

"This is going to feel like a return to the 1980s for people who lived in that era because suddenly information is back in the hands of the state," said Mr Alp Toker, director of NetBlocks, a London organisation that tracks Internet censorship.

Internet censorship efforts in Russia have grown for the past decade, said Dr Tanya Lokot, an associate professor at Dublin City University who specialises in digital rights in Eastern Europe.

Mr Putin first cracked down on government critics and independent news outlets online. Russia then began a campaign to install new censorship equipment to block or slow down access to websites like Twitter.

But the final break since the invasion began has jarred Russians who used the Internet to stay connected with the wider world, get independent information and build their careers.

Mr Alexei Pivovarov, who quit his job on state television almost a decade ago in the face of growing censorship, said he experienced a "second birth" when he started producing news shows and distributing them on YouTube. Almost three million people subscribe to his YouTube channel, where he and a team publish investigations and news reports that are unavailable on state media.

"I was completely sure that this part of my life was over forever, and I would never work as a journalist again," he said in a recent interview. "I never thought before I came to YouTube that it was possible." 

Now the work risks putting Mr Pivovarov in jail - or out of business. YouTube, which is owned by Google, last week blocked all Russian accounts from making money from their videos and barred Russian state television outlets from being shown across Europe. YouTube could be one of the next targets to be blocked by Russian regulators, experts predicted.

Mr Pivovarov, 47, who is based in Moscow, said he planned to keep broadcasting on YouTube despite the risks. But he said it was unclear how long he could keep going.

"For the moment I do plan to work in Russia," he said. "How this may change in the future, especially if YouTube will be blocked, I don't know."

Unlike China, where domestic Internet companies have grown into behemoths over more than a decade, Russia does not have a similarly vibrant domestic Internet or tech industry.

So as it is cordoned off into its own digital ecosystem, the fallout may be severe. In addition to access to independent information, the future reliability of Internet and telecommunications networks, as well as the availability of basic software and services used by businesses and government, is at risk.

Already, Russian telecom companies that operate mobile phone networks no longer have access to new equipment and services from companies like Nokia, Ericsson and Cisco. Efforts by Russian companies to develop new microprocessors were in doubt after Taiwan Semiconductor Manufacturing Co, the largest maker of essential semiconductors, halted shipments to the country.

Yandex, Russia's largest Internet company, with a search engine more widely used than Google in Russia, warned it might default on its debts because of the crisis.

"The whole IT, hardware and software market that Russia relies on is gravely damaged right now," said Dr Aliaksandr Herasmenka, a researcher at the University of Oxford's programme on democracy and technology. Russian authorities could respond by loosening rules that have made it illegal to download pirated software, he said.

The Ukrainian government has also pressured Internet service providers to sever access in Russia. Officials from Ukraine have asked ICANN, the nonprofit group that oversees Internet domains, to suspend the Russian Internet domain ".ru." The nonprofit has resisted these requests.

Mr Denis Lyashkov, a self-taught web developer with more than 15 years of experience, said Russia's censorship campaign was "devastating" for those who grew up with a less restricted Internet.

"I was 19 years old when I bought my first computer, and it was the best investment in my life," said Mr Lyashkov, who emigrated to Armenia from Moscow in the past week because of the growing restrictions. "When I started, it was a whole new world.

There were no borders, no censorship. Everyone could say anything they wanted."

Mr Lyashkov said that before he fled Russia, the company where he worked received a demand from the government to install new government certificates on its website, a technical change that could allow regulators to monitor traffic and potentially close the country's Internet to all but Russian or other approved websites. Last year, Russia tested taking such a step.

Some Russian Internet users appeared to be finding ways around tighter restrictions. Demand for virtual private networks, technology that lets people access blocked websites by masking their location, soared more than 600 per cent since the invasion, according to Top10VPN, a service that tracks usage of the technology.

But other decisions by multinational companies to punish Russia's aggression could make those circumvention tools harder to obtain. Many Russians who have VPNs pay for them using Visa and Mastercard, which have blocked payments in Russia.

"That move only helps the Kremlin in my view, unfortunately," Mr Pivovarov said.

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