What does thoreau say about serving your country through the military? why does he say this?

Thoreau was greatly opposed to military efforts such as the Mexican-American War but he was not inherently a pacifist. He believed it was in an individuals rights to choose not to support a war effort that they believed to be unjust. Therefore, it could be argued that he would support an individuals war efforts if the war was believed to be just and valued for the people, but if not then he would not support a soldiers service to the country through the military.