ANNOUNCER: Josie Santos from Fort Lauderdale asks: What is martial law?</s>EILEEN O'CONNOR, CNN NATIONAL CORRESPONDENT (on camera): Well, Josie, martial law is really the most extreme measure a president can take in wartime. It involves substituting the military for civilian authority. For instance, instead of police, it will be soldiers guarding the streets. (voice-over): The president who declares martial law must defend his decision by saying that the security and the welfare of the nation requires him to govern through the use of military force, and not through established law.
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