TAPA, Estonia - Heiko Porval, training nurse, demonstrates how to properly use a defibrillator during a refresher course with the U.S. and Estonian military medics, here, as part of Operation Atlantic Resolve Nov. 13, 2014. The U.S. Army Europe-led Atlantic Resolve, a multinational combined arms exercise involving the 1st Brigade Combat Team, 1st Cavalry Division, and host nations, takes place across Estonia, Latvia, Lithuania, and Poland to enhance multinational interoperability, to strengthen relationships among allied militaries, to contribute to regional stability, and to demonstrate U.S. commitment to NATO.