PBS NewsHour: How South Koreans are responding to pressure on North Korea from Trump

South Korea conducted more military drills Tuesday, the latest to deter North Korea after its nuclear test on Sunday. But there are growing concerns about U.S.-South Korea relations, as President Trump pushes South Korea to get tougher, threatening a trade deal and potentially driving a wedge between the two allies. William Brangham reports on the tensions rising with the Korean peninsula.