Because Russia is an enemy of the United States.
You live in the past. Russia is a friend and a future ally of the United States.
China is the real problem.
Can you list any dispute we have with Russia?
Uh, Crimea, Eastern Ukraine, South Ossetia, and the Baltics.
Also it's hideous human rights records and disgusting anti-LGBT bigotry.
Crimea used to be Russian territory before it was transferred to Ukraine by order of Nikita Khrushchev.
The population of Eastern Ukraine is majority Russian. Are you suggesting Russia should abandon them? After all, the government in Ukraine is fiercely anti-Russian. Russia didn't touch Ukraine while pro-Russian governments were in power there.
South Ossetia is ethnic Russian territory as well.
Last I heard, Russia hasn't invaded any of the Baltic States.
Human rights records are none of our business. Russians are more conservative and traditional than the other European nations, on average. Throughout history, the form of government in Russia has always been authoritarian. At least they have democracy and elections. Their democracy may not be a liberal democracy, but it's still a democracy and democracies are always better than dictatorships.