I believe one the biggest reasons for Hitler's rise into power was exactly Great Britain and France foreigner politics.
Politics was always included when war is starting. There's no war if no one will fund it and whoever is behind it is their ally in politics.
Are there good sides in a war?
What will be the good side of the war? there's too much casualty and innocent people will die, I guess the only ones that can say if there's a good side are the victors but overall, there's none.