Biodefense refers to measures to restore biosecurity to a group of organisms who are, or may be, subject to biological threats or infectious diseases. Biodefense is frequently discussed in the context of biowar or bioterrorism, and is generally considered a military or emergency response term. Biodefense applies to two distinct target populations: civilian non-combatant and military combatant (troops in the field). Protection of water supplies and food supplies are often a critical part of biodefense.