 Approximately 350 U.S. and 100 Romanian troops participated in the Proof of Principle.After the Proof of Principle exercise was completed, U.S. Army Europe issued an order for JTF-East to begin a period of “warm-basing” at the Mihail Kogălniceanu Airfield, Romania.The driver for this decision was the absence of any available rotational forces to occupy JTF-East due to the 2007 “surge” in Iraq, which significantly increased the number of troops deployed there.