The Visegrad 4 (comprising the Czech Republic, Poland, Hungary and Slovakia) should increase cooperation on defense, Czech Prime Minister Bohuslav Sobotka said on Thursday at a V4 meeting in Bratislava. Mr Sobotka stressed that NATO was the pillar of security in eastern and central Europe; the alliance has gained new urgency and purpose following Russia’s military intervention in Crimea and the amassment of Russian troops on Ukraine’s border. Poland’s Prime Minister Donald Tusk said he was in favour of a larger NATO presence – some 3,000 to 4,000 troops – on the alliance’s eastern border by 2016. Earlier this week, the Czech defence minister, Martin Stropnický, fumbled an interview with Reuters when he suggested a majority of Czechs would be unhappy with foreign troops on the ground, as they still remembered Soviet troops in the country after 1968. He later shifted his position, putting forward a declaration reaffirming the Czech Republic’s commitment to NATO. The declaration passed in the lower house on Wednesday.