The protection of borders between the Czechoslovak Socialist Republic (CSSR) and so called Capitalist countries of Western Europe, namely with West Germany and Austria, in the Cold War era and especially after 1951, was provided by special troops of the Pohranicní Stráž and system of engineer equipment which created the real "Iron Curtain". The purpose was to prevent citizens of the Eastern Bloc escaping to the West, although official reports stated it was to keep the enemy's spies and saboteurs out of Czechoslovakia. The border system of Czechoslovakia was not as elaborate and fortified as that of the East Germany, but it was considered difficult to cross the border undetected.