Answer:
Russia might be unhappy with both the former USSR and Warsaw Pact countries joining NATO after the collapse of communism in Europe for several reasons related to geographic location.
Firstly, the expansion of NATO to include these countries brings the military alliance closer to Russia's borders, which can be seen as a security threat. This is particularly concerning for Russia given that NATO has been involved in military actions in countries near Russia in the past, such as in Yugoslavia.
Secondly, the inclusion of these countries in NATO can also be seen as a loss of influence and prestige for Russia. The former USSR and Warsaw Pact countries were historically aligned with Russia during the Cold War and their inclusion in NATO can be viewed as a shift away from Russia's sphere of influence.
Lastly, Russia has historically had a strong cultural, economic, and political ties with the countries that were part of the former USSR and Warsaw Pact. The inclusion of these countries in NATO can be seen as a move to weaken these ties and a further erosion of Russia's power and prestige in the region.
All these reasons combined together, make Russia unhappy with the former USSR and Warsaw Pact countries joining NATO after the collapse of communism in Europe.