Operation Praying Mantis was an attack on 18 April 1988, by U.S. forces within Iranian territorial waters in retaliation for the Iranian mining of the Persian Gulf during the Iran–Iraq war and the subsequent damage to an American warship.On 14 April, the guided missile frigate USS Samuel B. Roberts struck a mine while deployed in the Persian Gulf as part of Operation Earnest Will, the 1987–88 convoy missions in which U.S.