How did Ireland secretly assist Britain and the United States during World War II?

While Ireland maintained a policy of official neutrality during World War II under the leadership of Eamon de Valera, the government secretly provided significant support to the Allies.

Despite facing intense pressure from Winston Churchill and Franklin D. Roosevelt to abandon its neutral stance, de Valera recognized that a German victory posed an existential threat to the sovereignty he had worked to establish. Consequently, Irish authorities covertly supplied the Allies with critical intelligence and other forms of assistance throughout the conflict. This cooperation was balanced against the government's public commitment to ensuring Ireland would not serve as a base for attacks against Great Britain, a policy enforced domestically through the Emergency Powers Act of 1939.1