Captain America Comics #21

One of Hitler's agents, the Creeper, steals a tri-rubied treaty ring in hopes of disrupting the signing of a treaty that pledges the last neutral European country to fight alongside the Allies, because he thinks that, when the U.S. ambassador Lissom signs the treaty without wearing the ring he was gifted by the ruler, the country will perceive a slight and choose to throw in with the Axis instead.