Vladimir Putin leaves a commemorative note at Kant Baltic Federal University where he also gave a talk to students - SPUTNIK/REUTERSVladimir Putin has raised fears of war with Nato by threatening the EU nations bordering Kaliningrad on a surprise visit to the Russian exclave. Fighter jets were deployed off the eastern coast of the Swedish island of Gotland as Putin approached the Baltic Sea. Talking to students at the Kant Baltic Federal University, Putin hit out at Kaliningrad’s neighbours for tearing down Soviet war memorials. In January, Boris Pistorius, the German defence minister, said Putin could declare war on Nato in “five to eight years”. Kaliningrad is viewed as the most likely place for a war to break out between Russia and Nato.