A national revolutionary army is a group of people organized to fight for their country. It is usually made up of soldiers, policemen, and other people who believe strongly in their country and want to protect it by fighting off anyone who threatens it. National revolutionary armies do not always fight foreign enemies, but can also fight to bring about change within their own country. For example, in some countries, groups of people with similar political beliefs may form a national revolutionary army to try to overthrow the government and replace it with one that they think would be better.