What is the feud between Russia and Ukraine?

Let's talk about historical issues first. The earliest country in Russia actually originated from Ukraine, which is the famous Kiev Russian Principality. Kiev Russian Principality is the predecessor of Ukraine, Belarus and Russia, three modern Eastern Slavic countries. Now Russia is based on the Principality of Moscow, so Ukrainians think that the country name of Russia should be "Moscow" or "Khartoum". Russian national culture originated from the Russian period in Kiev, when it accepted Norman (Nordic) culture and Byzantine culture and formed a unique Russian culture in Kiev. The status of Russian national culture in Kiev is equivalent to that of China in Xia, Shang and Zhou Dynasties, which is a foundation-laying era. Therefore, Ukrainians have always had a strong sense of cultural pride, especially in the era of tense relations between Russia and Ukraine. Ukrainians have a sense of superiority and mission of the Russian nation and often think that they are the authentic "Russia." Therefore, ethnic and cultural conflicts are the crux of the contradiction between Russia and Ukraine.

Let's talk about reality. During the civil war in Ukraine, due to Russia's instigation and support to the eastern region, the relationship between Ukraine and Russia's separated brother-in-law was deadlocked. On the 20th/Kloc-0th/4th Crimean Peninsula dispute, Russia welcomed its little Crimean brother home with open arms, but Ukraine had to watch a piece of meat on its body grow legs and go to someone else's house, so the relationship between Ukraine and Russia completely dropped to freezing point.