In their personal lives, they navigated Western culture, bonded with Western partners, vacationed in Europe and the United States and often studied there.

Mr. Pogosyan’s former superior, for instance, was a deputy energy minister, Pavel Sorokin, who studied in London and worked at Morgan Stanley. Mr. Sorokin, 37, has played a key role in maintaining Russia’s alliance with the Organization of Petroleum Producing Countries, which has helped prop up the Kremlin’s oil revenues, according to Mr. Pogosyan, who until his departure wrote the deputy minister’s press statements.

Another Russian technocrat, Mr. Putin’s chief economic adviser Maksim Oreshkin, 40, worked in the French bank Crédit Agricole and is fluent in English. He devised a payment system that allows Russia to sell gas to Europe in rubles, pre-empting Western sanctions, Bloomberg News reported last year, citing anonymous sources.

And Aleksei Sazanov, 40, an Oxford-educated deputy finance minister, works on maximizing Russian tax revenues from oil and gas exports hit by sanctions.

Mr. Sorokin and the press offices of Mr. Oreshkin and Mr. Sazanov did not immediately respond to requests for comment on their post-invasion initiatives.

The midlevel technocrats who opted to stay in most cases did not face explicit government threats or coercion, said Aleksandra Propokenko, a former monetary policy adviser at Russia’s Central Bank, who resigned and left the country shortly after the start of the war. Instead, she said, they are driven by a combination of professional opportunities, material benefits and inertia.

Mr. Putin’s calls for economic self-sufficiency have put a premium on their professional skills, Ms. Prokopenko said in an interview in Berlin. “They are becoming more visible to Putin, and they feel empowered.”