I need an excuse for this battle royale to work. Here's some background-- I need a reason that will fit into constraints of a world like this: World War III ensues, and nuclear bombings rock the world. It’s a battle on the home front, and citizens are dying by the masses while the leaders call the shots, waiting for the losses on other sides to rack up until they surrender in a grueling battle of attrition. Angered at the disregard for their lives the people rise up, capturing their leaders to make them fight in an arena upon the ruins of Britain, a war on a small scale. It would later become known as Arena 1, the first arena. Around the arena, a new ideology and civilization spring up, holding the belief that leaders should be those who protect their countries in exchange for their administrative power. Those affected by the destruction of WWIII jump aboard, realizing that this “organized war” would prevent the mass deaths of grand armies and helpless citizens. This is the establishment of the World Capital, the administrative power of the new age. Organizations of citizens agree to appoint leaders on the condition that they will fight should a war arise. Dangerous goods, such as nukes, are removed from countries and delivered to the World Capital as a means to enforce the rules of the game. Over time, it becomes common for leaders to send their children, as they are younger and stand a better chance in the arena while still preserving the sacrifice of those on top. The event becomes widely televised. I need a reason for several countries to "declare war" on eachother. Ideas?