About 2,000 NATO troops from the U.S., Britain and Poland conducted an airborne training operation on Tuesday as part of the biggest exercise performed in Poland since the 1989 end of communism and amid concerns over Russia, according to AP. Scores of U.S. troops and then military vehicles parachuted into a spacious, grassy training area on the outskirts of the central city of Torun. The force's mission was to secure a bridge on the Vistula River as part of the Polish-led Anakonda-16 exercise that involves about 31,000 troops and runs through mid-June. Nineteen NATO member nations and five partner nations are contributing troops to the exercise that will train and test their swift joint reaction to threats on land, sea and in the air.