In 1991, it was the former Secretary of State, James Baker that had promised President Gorbachev that NATO would NOT MOVE ONE INCH towards the East. Unfortunately, it was never in a signed agreement, only Baker's word. President Gorbachev had security concerns regarding NATO, it was that assurance from Baker after which the Russian President dissolved the Warsaw Pact. Of course we never kept our word which the Russians consider a very important aspect of true integrity. The Deep State had other plans and since then NATO has moved eastward by OVER 1100 MILES closer to Russian Federation territory, viewed by President Putin as a security threat. President Putin knew that Ukraine was next, being that the DS/NATO wanted to shut down the huge Russian Naval base on Crimea which would have exposed Russian waters to NATO hostilities. That's the short of it.