During the Great Depression, Hans Zinsser, a bacteriologist and historian wrote that "Infectious Disease is one of the few genuine adventures left in the world." "Infectious Disease is one of the great tragedies of living things - the struggle for existence between different forms of life . . Incessantly the pitiless war goes on, without quarter or armistice - a nationalism of species against species." Hans Zinsser- Rats, Lice and History (1934) Infectious Agents as Tools of Mass Casualties Bioterrorism , National Security and Law Historical Perspective and Trends Related to Bioterrorism