Guarding Europe's eastern flank

updated 13:42 PM GMT, Fri Nov 14, 2014
By Richard Allen Greene, Inez Torre and Kevin Taverner, CNN

NATO regularly keeps jets on standby in Eastern Europe as part of its Baltic Air Patrol mission, but since Russia laid claim to Ukraine's Crimean peninsula in the spring, NATO has boosted its fleet of planes. There used to be only four jets ready to intercept Russian planes that crossed into European airspace. Now there are 18. Slide the arrow to see the change.