Back in 2014, the CIA gave lots of money and weapons to people in the Western Ukraine that hated everything Russian. In 1750, the Russian Empire ended at the Dnieper River. During the next 50 years, the Russian Empire annexed 60% of the Polish Empire, and they all hated it. After WWI, the US wanted to end all the European Empires, and the UK and France agreed to end all the other European Empires, so Russia lost all of the Polish Empire that it annexed in the 18th century, and the Poles that had been in the Russian Empire were very happy to be liberated.
Then, at the beginning of WWII, Stalin took back everything the Allies took after WWI plus bits of what had been the Austrian Empire before WWI, and they all hated it. Those in reclaimed Ukraine west of the Dnieper River felt they were liberated by the Wehrmacht in 1941, but then the USSR won and they were returned to the Soviet Socialist Republic of Ukraine, and hated it. And then, in 1954, Khrushchev transferred the Crimea from the Soviet Socialist Russian Republic to the Soviet Socialist Ukrainian Republic.
After the USSR collapsed, a majority in the Ukraine voted to make the entire Ukraine into an independent nation. But, for 14 years, the government was strongly pro-Russian, meaning they let all the citizens speak whatever language they preferred, send their children to schools in whatever language they preferred, and go to whatever church they liked.
But the Western Ukrainians with US money and weapons took over and put in a neutral president who said the Russian language and the Russian Orthodox religion were strictly banned throughout the entire Ukraine, and ordered all the Russian military bases in the Crimea closed.
So Putin declared the Donbass, which wanted independence, an autonomous part of the Ukraine where the Russian language and the Russian Orthodox religion were allowed. This was a heinous violation of International Law, since the official government said they were banned. Putin also called for an illegal election in the Crimea where just about everyone voted to return to Russia, again, illegal, and condemned by the rest of the world. Or at least by the rest of the world that counts: NATO!
But that was all Putin could do in 2014. NATO say he must give back the Crimea, and he must let the Ukraine enforce the law in the Donbass, and they plan to help the Ukraine enforce those laws, and say if Putin interferes, they will cut Russia off from SWIFT and the Europeans won't buy any more of that evil Russian gas, they'll buy Democratic US LNG. Costs a bit more, but it's Democratic gas, so it's worth it. Putin remains unhappy with what happened in the Ukraine, but isn't sure what he can do about it. And NATO remain unhappy with the current state of the Ukraine, and might do something about it.
Then, in 2021, the CIA gave lots of money and weapons to a group that hated everything Russian and everything Chinese in Kazakhstan, and it looked like they were about to take over the government and set up a new, democratic government that would ban the Russians and the Chinese from Kazakhstan, putting a big dent in the New Silk Road. Things were going great for the CIA for about half a day, when 2,000 troops from a multi-national security group Putin had put together from several of the former Soviet states flew in to Kazakhstan and the great CIA attempt to liberate Kazakhstan was put down and several thousand good, hard-working CIA employees were gaoled. The PRC can continue to improve the New Silk Road through Kazakhstan where they have about $25 billion already invested, and plan to invest a lot more. And Kazakhstan remain good friends with Russia.
It seems Russia have more options now than they had back in 2014. And I assume Putin wishes he'd had those same options in 2014 so the Ukraine would not be the mess it is now.