FILE - In this Thursday, May 7, 1992, file photo, Spc. Valorie Love, left, and Spc. Robert Hill, both from the National Guard, keep a close eye on the activity near Los Angeles City Hall. On Monday, Aug. 18, 2014, Missouri Gov. Jay Nixon ordered the National Guard to Ferguson, Mo., to help restore order, while lifting a midnight-to-5 a.m. curfew that had been in place for two days, following the shooting death of unarmed black teenager Michael Brown, by police. National Guard members have frequently been called on to help out in natural disasters, but there also is a history of units being deployed to quell civil unrest, such as in the 1992 Los Angeles riots. (AP Photo/Chris Martinez, File)