NATO expanded long before Putin.

Ukraine joined NATO's Partnership for Peace in 1994 and the NATO-Ukraine Commission in 1997, then agreed the NATO-Ukraine Action Plan in 2002 and entered into NATO's Intensified Dialogue program in 2005.

Over the course of the 1990s and early 2000s, NATO expanded three times: first to add the Czech Republic, Hungary and Poland; then seven more countries even farther east, including the former Soviet republics of Estonia, Latvia and Lithuania; and finally with Albania and Croatia in 2009. 

During the early 2000s, President George W. Bush pushed for Ukraine to become a NATO member. France and Germany opposed it, fearing escalation with Russia. 

Read some history