Martial law
(Book)

"After natural disasters and economic difficulties have left the United States on the edge of collapse, the nation's major cities are becoming lawless battlgrounds. Nathan Foster and Marie Shaw find themselves trapped in Chicago, where they must outwit their enemies if they hope to reunite with their families. When the U.S. President makes the crucial decision to allow peacekeepers from the United Nations to help restore order, the nation hopes it will put them back on their feet. However, when a major earthquake strikes, the true intentions of the U.N. forces become more evident"--,http://deseretbook.com.