Why is Ukraine in chaos?

The struggle between pro-Russian and pro-European factions in Ukraine has always been pro-Russian in history. But after independence, pro-Europeans gradually gained momentum. This time, the Ukrainian president shelved the negotiations on joining the European Union, which triggered a large-scale pro-European protest. Because this is related to Ukraine's national luck, no matter the east or the west, there is no way to reconcile the contradictions between the two factions, which may lead to civil war.