4. Trump Confronts NATO's Free Riders NATO is a 28-nation defence alliance that regards an attack on one member as an attack on every member. To provide the agreed level of mutual support, NATO members commit to spending at least 2 percent of their gross domestic product on defence. But only the United States, Britain, Poland, Estonia, and Greece beat 2 percent. France, Germany, and Canada fall short. Source: The Chicago Tribune, February 16, 2017 a. Explain the free-rider problem described in this news clip. b. Does the free-rider problem in international defence mean that the world has too little defence against aggression? c. How do nations try to overcome the free-rider problem among nations