These nations were captive because their foreign policies were dictated by Moscow, just as these same Captive Nations, plus the UK, Western Europe, Canada, Mexico, Columbia, Japan, Australia, New Zealand, South Korea, Taiwan, the Philippines, Georgia, and Ukraine, have their foreign policies dictated today by Washington. Washington intends to expand the Captive Nations to include Azerbaijan, former constituent parts of Soviet Central Asia, Vietnam, Thailand, and Indonesia.
During the Cold War Americans thought of Western Europe and Great Britain as independent sovereign countries. Whether they were or not, they most certainly are not today. We are now almost seven decades after WWII, and US troops still occupy Germany. No European government dares to take a stance different from that of the US Department of State.