Secretary of State Rex Tillerson this week became the latest U.S. official to say Russia was supplying arms to the Afghan Taliban, calling it a violation of international norms. His remarks, which came just days after President Trump announced a new open-ended U.S. military commitment to Afghanistan, echo those of General John Nicholson, the head of U.S. and international forces in Afghanistan, and Army General Curtis Scaparrotti, commander of the U.S. European Command. Russia, which has been critical of U.S. policy in Afghanistan, has vehemently denied the accusations.