How will Mars be divided among the nations of the Earth?

As I write my first paper, I have begun to wonder how Mars will be divided among the nations of the Earth. Will countries without space travel programs be allowed to colonize Mars? What will be the fate of countries that are too poor to afford Mars colonies? Will Martians associate themselves with their home countries, or will they simply be Martians? These questions will have to be addressed by the United Nations in the near future.