美国历史上，一共发起了四百余场军事行动，其中大部分是“不宣而战”。美国宪法中规定的总统和国会的战争权制衡机制早已失效，而这正是美国战争“泛滥”的一大根源。美国总统何以“不宣而战”？他们又是怎样避开国会，独霸战争权的？本期《真相放大镜》为你揭晓。The U.S. is a country with the separation of powers, yet it led to the dominant position of war powers dangling between Congress and the president. Why are there hundreds of American wars that started without a declaration? How much power does a U.S. President have in waging a military operation outside the country? This episode of Facts Tell helps you find out. 推荐阅读： 真相放大镜 | 美军在叙利亚频繁“偷油”备受争议，究竟图什么？ 真相放大镜 | 美国出台芯片法案意欲何为？ 真相放大镜 | 谁允许日本向太平洋倾倒核污水？