I am writing a YA novel that more or less takes place in the future. I need a few tips about the villain. A little backstory: A genetic research project goes terribly wrong and a bunch of wild 10 feet lizards are let on the loose and the humankind is on the brink of destruction. However they manage to hold the lizards of for long enough to build huge walls around large cities surrounded by wastelands occupied by said lizards. Inside this cites life eventually goes on as before, and little by little they manage to build up a society again over the course of couple hundred years. As the lizards are mating and multiplying it gets dangerous leaving the safety of the cities. They still have global communication thanks to satellites, and the whole world are united in an effort to eradicate the lizards. In order to do so, every year the capital sends a plane to each of the cites to gather every male over 16 who volunteer to join the military. The cities are democratic and elect a new government every third year, the citizens pay taxes, work, and are basically living the same life as we do now. Only they can't leave the city. There are no laws against it, but it is recommended that they stay inside the safety of the walls. Everyone who wants leave however, are free to do so. They have their struggles like every other society of course, but it's as good as it gets, or so it seems to the citizens. What they don't know is that there are not many cities left. Most of the world is in ruins, but the few cities left believes that the world is slowly rebuilding. The truth is that there are 3 or 4 large cities in addition to the capital. The lizards are real enough, but they are not so wild as people believe them to be. They are in fact controlled by the government. Shortly after the failed experiment, they regained control over the lizards, but still let them loose on the world. The youths who are recruited to the military is really recruited to work as slaves for the capital. The global communication is also partly a lie. Though the cities can communicate between each other, the government still monitors it. When they "communicate" with a city that doesn't exists anymore, it's really a studio in the capital they communicate with. People that leaves the city are hunted down for sports by the lizards, and shown on the big screen. The people of the capital doesn't know about the other cities, and believe the capital to be the only one left in the entire world. They believe that the lizards spread a virus that killed everybody else. The people that are hunted down by lizards are believed to be infected people, and people hope the lizards will die of it. So far so good, but my problem is simple: Why do the government do this? What motivation do they have? What have they to gain, as the people of the cities also live good and healthy lives. Obviously there are the salves they gather once a year, but they need more of a motivation to do this if they are gonna let the people live as they are free. Any tips and criticism are received with gratitude. Questions are also welcome, but this is a rough first draft and probably not as the polished end product will look like.