The war between Russia and Ukraine does not begin in 2021 or 2014. Rather in the 9th century.
Let’s go back to the 9th Century, there was a state called Kievan Rus, whose capital was Kiev.
Between 980-1015 Kievan Rus was ruled by Grand Prince Volodimer. In Russian accent his name is Vladimir where as in Ukrainian accent his name was Volodimer and coincidentally these are also the names of the president of these two countries today. Anyways Russians and Ukrainians draw their birth from this slavic state. A lot changed in the following centuries. In fact Ukraine was under the Russian rule.
In the 1900s these two were Soviet Republics. Russia was the most powerful and Ukraine the second most powerful of the 15 republics.
The Soviet Union collapsed in 1991 for which russia and Ukraine became independent. Ukraine gave its nuclear arsenal to russia in 1994, in exchange Moscow guaranteed Ukraine’s safety.
In November 13, Viktor Yanukovych became th president of Ukraine who was openly reputed for corruption and pro-moscow. He had done many great works for which the Ukrainian public got angry amd protest broke out.
In February, 2014 finally the empire of Yanukovych ended. Not every Ukrainian was happy with this. Russia was angry because he had lost his puppet. In annoyance he annexed Crimea, a state gifted to Ukraine from Russia by Soviet Leader Nikita Khrushchev in 1954.
Before moving further I would like to point out one important thing, since the Soviet Union broken apart Russia always been creating disturbances between his neighbouring countries every 6-7 years. In 2008 Russia occupied some areas of Georgia and as I already mentioned in 2014 it annexed Crimea. Now in 2022 it is trying to do a world war III.
So these are the russian possible routes to attack Ukraine.
Praying to god this conflict not be the next world War because we already lost many lives for Covid, not any more.
Fun Fact :
Many including me believe that China has pressurised Russia to not to do any kind of war or disturbances till the end of Beijing Olympics, which will decrease the chinese reputation. By the way after the beijing olympics ended that is on 20th February Vladimir Putin addressed the entire world the two separist state (Donetsk and Luhansk) will now be recognised as independents.
 Encyclopaedia Britannica.com
 Republic World.com