Yes, both the United States and the United Kingdom were involved in the Dunkirk operation. The operation, codenamed Operation Dynamo, was a mass evacuation of Allied forces from the French port of Dunkirk during World War II. The evacuation began on May 26, 1940, and lasted for eight days, until June 4. During that time, over 338,000 troops were rescued from the beaches and harbor of Dunkirk. The evacuation was made possible by the heroic efforts of the British Royal Navy, the Royal Air Force, and thousands of civilian volunteers. The United States played a supporting role in the operation by providing logistical support and some naval vessels.