ARLINGTON, Va., March 24 (UPI) -- The return of Russia as a world power comes after a brief, economically driven absence in the late 1990s. Russia has been through periods of inward retrenchment before. However, with control over massive oil and gas reserves, Russia has re-emerged as a powerhouse. Now that nation is causing friction around its borders on issues from energy supplies to missile defense. New member states of the U.S.-led North Atlantic Treaty Organization have been particular targets.