A soldier participates in "Saber Strike 2017" exercise at a military base in Tapa, Estonia, on June 14, 2017. "Saber Strike" is a multinational combined forces exercise which helps to facilitate cooperation among NATO allies and partner nation focusing on promoting interoperability, and improving joint operational capability. It took place in multiple locations throughout Poland and Baltic countries from May 28 to June 24. (Xinhua/Sergei Stepanov)
