
KIRKENES, Norway—Early in the day on Dec. 5, 2017, Frode Berg, a 62-year-old pensioner and former border guard from Norway, posted a photo of a snow-covered Red Square on his Facebook page with the caption “Christmas time in Moscow!”
Berg had left his home in Kirkenes, a Norwegian town of about 3,500 people near the country’s 121-mile Arctic border with Russia, a day earlier for a weekend trip to the Russian capital. He said he was visiting friends and doing some Christmas shopping. But he never returned.