Cohen was a realist , like Mearsheimer, Cohen saw shades in Eastern bloc, he did not see JeffreySachs Yeltsin era as a liberal WesternDemocracy, it was Washington district of Columbia and State (statedepartment) that envision Russia as a (future) liberal western democracyYes, he seems to have, subconciously at least, held the belief that pre-Putin Russia was some sort of Western liberal democratic paradise that was going to be a partner with the US, which Putin ruined by doing Putin things - you know, evil things.
Well, maybe not quite, but he seems to sincerely believe that Yeltsin's Russia was a somewhat functional democratic state that was transitioning away from its Soviet past and would eventually became a Poland.
Unfortunately:
1) Yeltsin's regime was a hybrid regime with incredible amounts of corruption (police officers were openly asking citizens for bribes, which pretty much stopped under Putin)
2) The quality of Russian leadership, and the integrity of Russian 'democracy', was such that the US had to help Yeltsin win an election against a literal Communist
3) Transition really meant collapse
Putin has made mistakes - it's not clear what his goal in Ukraine actually was, and he's failed to diversify the Russian economy away from oil and commodities properly. That we've also failed to that doesn't mean that he shouldn't have, especially since a more diversified economy makes you less vulnerable to sanctions.
