Protecting the territorial sovereignty of countries internationally would have prevented Iraq and Afghanistan. It would stop Israeli efforts in the West Bank. It would block the Armenia-Azerbaijan conflict. It would block the skirmishes between India and China as well as India and Pakistan. It would have blocked NATO intervention into the Yugoslav crisises until international consensus could be reached. Borders are constantly in a state of flux and the international community almost never reaches full consensus.
Borders are not immutable objects, particularly for ethnically-unified countries. For Yugoslavia, the borders were carved into ethnic groups. For Ukraine, the borders are being carved into Russian and Ukrainian areas. For Israel, the borders are constantly being expanded for one particular ethnic group. As long as there are ethnic boundaries, there will be conflict between them. That’s what makes us human. We are not a single entity; we have hundreds of distinct and unique cultures and languages and foods.