In addition to their most recent support of homeland security operations around the country, PSUs were first deployed to the Persian Gulf during Operation Desert Storm in 1990. They also served in Haiti during Operation Uphold Democracy in 1994 and more recently responded to Port-au-Prince, Haiti immediately after the devastating 2010 earthquake. In December 2000, PSU 309 from Port Clinton, Ohio was deployed to the Middle East to provide vital force protection for the Navy assets following the attack on the USS "Cole".