I believe that natural causes and disasters should play a role in this game. Each country should get three lives. These causes will determine whether they survive or not. If they are attacked by one of the diseases or natural causes then they must use one of their lives. Also once one of them may be destroyed- other countries may help you if they want, or if you have no help you must find the means on your own to rebuild all that you lost. If all 3 of your lives are lost then your village will desimated.