Why did Eamon de Valera declare Ireland neutral in World War II?

Eamon de Valera’s decision to declare Ireland neutral at the outbreak of World War II in 1939 was the culmination of his long-standing republican aspiration to establish full Irish sovereignty.12

This policy was made possible by the Anglo-Irish defense agreement of April 1938, in which de Valera negotiated the return of three strategic naval bases—Cobh, Berehaven, and Lough Swilly—that had been retained by Britain under the 1921 treaty. By securing these bases and settling related financial and trade disputes, de Valera successfully removed the primary obstacles to an independent foreign policy.12

For de Valera, neutrality served as the ultimate expression of Ireland’s hard-won independence. Although he maintained a policy of official neutrality despite significant pressure from Winston Churchill and Franklin D. Roosevelt, he secretly authorized intelligence and military assistance to the Allies. He recognized that a German victory would ultimately threaten the very sovereignty he had worked to secure.12