Other mistake: In the private conversation scene with Bill Murray and "Sarge" in the latrine at basic (Sarge's office) the toilet bowl in the back left corner is installed backwards. (00:43:03 - 00:45:10)
Other mistake: During the graduation scene, if you watch as the platoons are marching by, you can see that several members are not in cadence as they should be. This also includes the men walking between the platoons that are supposed to be setting the cadence and they are out of step with the platoon in front and behind them.
Answer: In 1981 Czechoslovakia was part of the Warsaw Pact and thus under the Iron Curtain. The Soviet Union would not fully allow the satellite states to do their own border security, so Soviet guards were placed.
lionhead