I should have said, they have complained about NATO expansion since the fall of the USSR (and obviously before, but that's irrelevant), when NATO gave Gorbachev

I should have said, they have complained about NATO expansion since the fall of the USSR (and obviously before, but that's irrelevant), when NATO gave Gorbachev assurances that NATO would not expand "one inch eastward" after German reunification. They've been very vocally critical of NATO expansion into Ukraine for 15 years (and probably longer), and the West has known that Ukraine was specifically significant for 15 years (and probably longer).