The last remaining nuclear treaty between the U.S. and Russia has expired, ending decades of arms control between the two countries with the largest nuclear arsenals.
A police helicopter crashed near the scene of what authorities in Flagstaff, Arizona called "an active officer-involved shooting investigation," according to police in Page, Arizona.
President Trump is awarding the Medal of Honor to a pilot whose faceoff with Soviet fighter jets remained secret for a half-century and a soldier who died in Afghanistan while shielding somebody from a suicide bomber.