The claim is reasonably accurate. In regards to foreign policy, the Warsaw Pact nations replicated the ideas of the USSR. Moreover, when a communist nation in Eastern Europe "disobeyed" the USSR, there were quite dire consequences. The Tito-Stalin split is now widely regarded as an issue of Yugoslav autonomy, where Stalin didn't want Tito to have as much power as he did.

You can see in the 1956 invasion of Hungary, and the 1968 invasion of Czechoslovakia, just how much Soviet leaders would do to maintain their handle on their puppets in government. They went in when leaders didn't do what they wanted, and so deposed them to set up a more pro-Soviet government. In fact, without direct Soviet support, the communist governments in eastern europe collapsed.

One of the main reasons for the collapse of the Soviet Empire, was Gorbachev's unwillingness to support eastern european leaders. Without Soviet support, eastern european communist leaders fell quite quickly.

In regards to NATO, and the US, no, you could not say the same. Every NATO member state was a fully autonomous sovereign state, and America never used force to coerce a NATO member into any particular action. However, you could argue that it was "dollar imperialism" as the Soviet's put it. While the US didn't directly have control over NATO member states, through the marshall plan and economic control, the US did wield extensive influence over NATO members, and was able to effectively control their actions to an extent.