Spy or Not? American Who Loves Russia Ensnared in New Cold War

He had visited Russia since at least 2006 — the trip that year was part of a special military furlough program — and was familiar to numerous Russians who had known him or interacted with him on social media. They said he seemed to pop up every six months or so. Unusual for an occasional visitor, Mr. Whelan had an account on Vkontakte, the Russian version of Facebook, for about a decade.

He did not post often, but wrote congratulatory notes in Russian on various major holidays and occasionally voiced his opinions about American politics. “GOD SAVE PRESIDENT TRUMP!!” Mr. Whelan wrote on the day of Mr. Trump’s inauguration in January 2017, bracketing the sentence with two American flag emojis. After Russia annexed Crimea in 2014, he posted a Russian cartoon suggesting that Alaska might be next, as it was once a Russian territory. “Putin can have Alaska, as long as he takes Sarah Palin, too!!” Mr. Whelan wrote.

Last August, he wrote that his cat, Mittens, a pet for 16 years, had passed away. “Farewell to a loyal friend of many years,” Mr. Whelan posted.