U.S. and other Western nations have carried out exercises on NATO’s eastern flank in past years, but the new deployment — which includes some 3,500 U.S. troops — marks the first-ever continuous deployment to the region by a NATO ally.

US troops enter Poland, 1st deployment at Russia’s doorstep | 12 Jan 2017 – (apnews.com) | American soldiers rolled into Poland on Thursday, fulfilling a dream some Poles have had since the fall of communism in 1989 to have U.S. troops on their soil as a deterrent against Russia. Some people waved and held up American flags as U.S. troops in tanks and other vehicles crossed into southwestern Poland from Germany and headed toward the town of Zagan, where they will be based. Poland’s prime minister and defense minister will welcome them in an official ceremony Saturday.

US tanks and soldiers in Poland pose threat to Russia – Kremlin | 13 Jan 2017 – (rt.com) | Russia sees the deployment of US tanks and other military vehicles, along with army personnel, as a threat to its national security and interests, Kremlin press secretary Dmitry Peskov said. “We see this as a threat. These actions pose a threat to our interests and security,” Peskov told journalists on Thursday, stressing “especially, when a third country is beefing up its military presence along our borders with Europe. And this is not even a European country,” he added. Eighty-seven battle tanks, 144 Bradley fighting vehicles, and over 3,000 soldiers are on their way from Germany to Poland.