Issued during World War II, this striking 3 centavos red stamp from the Republic of Cuba features an allegorical female figure pressing her finger to her lips, symbolizing silence. The inscription warns: “¡Cuidado! La Quinta Columna te espía!” (“Beware! The Fifth Column is spying on you!”). It was part of a wartime propaganda series reminding citizens to guard against espionage and sabotage. A powerful historical piece, it reflects Cuba’s role in the global conflict and the era’s use of postal propaganda to shape public behavior. Highly sought after by collectors of wartime issues and Cuban philately.