Argentina had a surprise on July 10, 1945: The German submarine U-530 turned up at Mar del Plata and surrendered. Commander Otto Wermuth said that he’d received orders on May 8 to cease hostilities and proceed to the nearest United Nations port for surrender. He’d thought this was an enemy trick and decided to intern his submarine and crew in a neutral country. He chose Argentina thinking that it had not declared war and turned up there two months after the German surrender. That created a fertile field for speculation that the sub had been transporting Nazi gold or leaders...