American paratroopers from 1st Battalion, 503rd Infantry Regiment, 173rd Airborne Brigade and Romanian army paratroopers from the 6th Special Operations Brigade conduct a combined parachute operation at the beginning of Exercise Rubicon at Luna Drop Zone, Luna, Romania, Nov. 14. Rubicon is a U.S.-Romanian exercise designed to increase NATO interoperability between the two forces through partnered tactical training and allied airborne operations.