Russia poses the primary international threat to Sweden’s security, and foreign adversaries may seek to exploit the heightened risk of extremist violence from Islamists and far-right groups, according to the head of Sweden’s security service, Charlotte von Essen. “We must all learn to live with the serious security situation. Above all Russia, but also China and Iran continue to constitute the biggest threat to Sweden and they are working and to a certain extent also working together to change the current security system,” she said. Last August, the agency raised its assessment of the level of…