Read on Twitter
One of the interesting things I've discovered in my research on NATO enlargement and Russia is just how diverse the historiography of the question is, both in Russia and the West.
I thought at first that you'd have mainstream narratives (the West: Russia is to blame, Russia: the West is to blame) but there's a lot more nuance on both sides when you go beyond the media buzz, delving into actual academic studies.
Check out William Hill's No Place fo Russia (Columbia UP, 2018): https://cup.columbia.edu/book/no-place-for-russia/9780231704588. Here's what he has to say about NATO's enlargement. 
"Irrespective of subsequent events and causes, the very substance and justification of the 1993 decision to enlarge NATO at the very least greatly increased the possibility, and perhaps the likelihood, of an eventual new political and security division in Europe." (p. 116)
Hill's bio: "William H. Hill is a retired U.S. foreign service officer and Global Fellow at the Woodrow Wilson International Center for Scholars in Washington, DC. He served two terms as head of the OSCE Mission to Moldova between 1999 and 2006."
