Conscription is a government policy that requires citizens to serve in the military for a certain period. This practice is often implemented during times of war or national emergency when volunteer enlistments are insufficient. Countries may have different rules regarding age, duration, and exemptions for conscription. In many nations, conscription is seen as a way to ensure that the military has enough personnel to defend the country. Some notable examples of conscription include the United States during the Vietnam War and Israel, where military service is mandatory for most citizens.