What phrase immortalized the civilian and military effort to rescue Allied soldiers from France during WWII?

The phrase you're looking for is "The Dunkirk Spirit." To understand why, let's rewind to 1940. Nazi Germany's forces had pushed Allied troops, mainly British and French, to the beaches of Dunkirk in northern France. They were trapped, facing almost certain capture or death. Operation Dynamo was launched, a daring plan to evacuate these soldiers. What made it extraordinary wasn't just the Royal Navy's involvement, but the hundreds of civilian boats – fishing boats, pleasure cruisers, anything that could float – that sailed across the English Channel to rescue the troops. This incredible display of courage, resilience, and community spirit, where ordinary citizens risked their lives to help, became known as "The Dunkirk Spirit." It represents the determination to overcome adversity through unity and bravery. While "The Blitz" refers to the intense bombing campaign against Britain, and "The Great Escape" was a daring escape from a prisoner-of-war camp, neither capture the essence of that specific civilian-military rescue effort at Dunkirk.