KC-135 Stratotankers of the 100th ARW (Air Refueling Wing) from RAF Mildenhall are supporting NATO planes over Eastern Europe.
There’s a lot of aircraft currently operating over Romania and Poland, following Russia’s annexiation of Crimea.
Among them, the KC-135 tankers refueling the E-3 AWACS of the Royal Air Force and French Air Force (as the one in the image) that NATO deployed close to Ukraine in order to monitor the air activity of Russian planes amassing near the border.
Image credit: U.S. Air Force
a french air force E3F, so say the wing roundels and the removed boom.