Two events may have dramatically influences Russias course:
- The involvement of western forces in the economic collapse, such as currency speculations against the Ruble that contributed, or the George Soros political influence.
- The expansion of NATO eastwards despite promises to the contrary. Russia gave up its control of eastern Germany and allowed the reunification of Germany on the condition that NATO does not expand eastwards towards the Russian border. That promise as broken and today NATO forces are stationed exactly where Russia was afraid of them - directly at the Russian border.
When the people you try to befriend behave themselves like that towards you (meddling in your internal affairs, massively damaging your economy and possibly preparing for a government overthrow, breaking their promises and making your fears come true) then you would distance yourself from them as well, right?