Ukraine Russia War - an honest conversation with You

Russia was fine until Ukraine shelled Russian territory. Once that happened I figured it was game on and I wasn't wrong. If the West gets directly involved so will China. They can't allow Russia to fail because they don't want Western force's camped on their land border. If China gets involved it'll go nuclear quickly. I could be wrong on the last point but I doubt it. I'd be willing to wager money on it.