Hungary, Poland and the Czech Republic joined the North Atlantic Treaty Organisation (NATO) in 1999, a decade after the demise of Moscow-backed communism in eastern Europe.
Slovakia joined five years later, expanding the alliance to 26 members alongside other former communist states Bulgaria, Estonia, Latvia, Lithuania, Romania and Slovenia - despite Moscow's opposition.
Poland's Mateusz Morawiecki, Hungary's Victor Orban, Czech Republic's Andrej Babis and Slovakia's Peter Pellegrini met for a ceremony in Warsaw with the 1st Armoured Brigade, whose soldiers will soon join a NATO mission in Afghanistan.
Polish soldiers simulated an attack on enemy's positions with armoured vehicles, tanks, helicopters, and F-16 fighters flying over.
Autor: gf / Źródło: TVN24 News in English, Reuters