Kennedy put nukes in Turkey. Kruschev sailed nukes to Cuba. Kennedy sent US Navy boats to intercept.
Kennedy and Kruschev agreed to stand down and remove their nukes. The crisis was over.
After the Fall of the USSR, the US grabbed some of the old USSR. Russia was too weak to respond. Now Russia has responded by recovering Ukraine.
Ukraine and Belarus are part of the old Russia from 800 years ago. The Mongol Golden Horde came from the North of China, 3500 miles ways, and conquered Russia all the way to East Germany, Palestine, Northern India, including Poland, Hungary, Yugoslavia, Turkey, etc. The Mongols established suzerainty over Western Europe, Mediterranean, Vatican, etc.
For 300 years, the Mongols raised and harvested millions of half-breed Asian-White slaves for sale at Crimea slave markets. There are various names used today for the slaves are Slavs, Tatars, Eastern Europeans.
The greatest, largest land empire in history splintered from Golden Hordes and White Horde into dozens of Khanates (colonies) spread from China, Korea, to East Germany, N India,, etc. Ny the 1500's the empire began to collapse. Returning slaves settled in Ukraine and Belarus none could speak Russian and they eventually spoke a very close Russian dialect.
That's why Putin won't allow Ukraine nor Belarus to be taken by NATO, EU, USA. Russia can't let them go. It's too emotional for Russians to be reminded of the Hordes, Khanates, Crimea Slave markets, etc.
The US and West Europe sluff it off. Russia is serious and is recovering Ukraine now.