Defense alliances are agreements between countries to support each other in case of military threats or attacks. These alliances are formed to enhance security and deter potential aggressors by showing that an attack on one member will lead to a collective response from all members. A well-known example of a defense alliance is the North Atlantic Treaty Organization (NATO), which includes countries from North America and Europe. Members of defense alliances often engage in joint military exercises, share intelligence, and collaborate on defense strategies. These partnerships can strengthen national security and promote stability in regions where tensions may arise. Additionally, defense alliances can help smaller nations feel more secure by providing them with the backing of larger, more powerful allies.