An influential Pentagon advisory board has recommended the U.S. military quickly develop and field an interim capability to defeat hypersonic weapon threats, launching a program to develop a defensive capability against a new-class of ultra-high-speed strike systems that are the focus of an race between Washington, Beijing and Moscow. Missile Defense Agency Director Lt. Gen. Sam Greaves previewed findings of the not-yet-public Defense Science Board's 2017 summer study on hypersonic strike weapons in written testimony prepared for the Senate Armed...