Um... Really? Last I checked Russia increased its territory with the return of Crimea. If you mean the lands of Malorossia and Novorossia, they were chopped off from Russia by Lenin 100 years ago, and not 50. Same with Belorussia.
May I suggest that you refine the quality of your posts to something that is at least remotely historical accurate.
The Russians should blame themselves. In the mid 1990s, Ukraine wanted to merge with Russia, to create a Union state. It was Boris Yeltsin who turned down that proposal, after consulting with Bill Clinton. And in the late 1990s, the same happened with a proposal to merge Russia and Belarus. Yeltsin should have been toppled before he was able to destroy the RF.
In which case you'd remember that there was an attempt to democratically impeach Yeltsin in November 1993, when it became clear where he was leading the country (to destruction), and the bloody US-sponsored de-facto coup which followed - with tanks in Moscow shooting at the Parliament, something that kept Yeltsin and hime American advisors in power for 7 more years (in a way Russia between 1994 and 2000 was not much different from Ukraine of 2014 onwards)...
In 1991 Russians were naive, after 1993 and until 2000 the Russians were enslaved...
PS: As an additional answer to virtualx: if Russia were to respond no to the American actions in the same way USSR did back then, Russia would have needed to conduct a coup in Canada, install 5-6 military bases in Mexico and a couple on Cuba, and then sponsor a bunch of NGOs in USA to scream in all American media that the Obama regime must be toppled, all the while complaining in the same media that under Obama there is no freedom of speech in the USA.