Operation Greif - During the Battle of the Bulge in 1944, units of English speaking German soldiers used captured American and British uniforms, vehicles and equipment to slip behind Allied lines with the intent of causing chaos. The units were unable to achieve the primary goal of capturing and destroying bridges, but they did succeed in creating confusion by passing false orders and misdirecting Allied troops. In addition, the operation caused panic with the U.S. command when news spread that any soldier in American uniforms could actually be a German saboteur, culminating in the fear that these infiltrators would attempt to capture General Dwight Eisenhower.
Blue House Raid - On January 21, 1968, North Korea attempted to assassinate South Korean President Park Chung Hee by sending 31 elite commandos into Seoul disguised as South Korean soldiers. The infiltrators managed to get close the president’s residence at the Blue House before they were challenged by security and exposed. They fled and spent the following week trying to battle their way back to the DMZ. Ultimately they were all hunted down and killed except one who was captured (though it is possible that another managed to escape). It was while U.S. and Republic of Korea forces were pursing the commandos that the USS Pueblo was seized by North Korea, making it one of the few U.S. ships lost since WWII  .
Seizure of the steamer St. Nicholas 1861 - Disguised as a French coquette, Confederate officer Richard Thomas Zarvona hijacked the steamer St. Nicholas in Baltimore. After seizing the vessel, Zarvona conducted several raids on ships in the Chesapeake Bay diverting the cargo to the South. Hailed as a hero on his return to Richmond, Zarvona disguised himself as “The French Lady,” again with the goal of capturing another ship but was ultimately caught and imprisoned by the Union.