The movie “Dunkirk,’’ which opens on Friday, chronicles the epic 1940 evacuation from the French coast of more than 330,000 British and other Allied troops as German forces closed in on all sides. Metro Minute asked Kenneth Rendell, founder and director of the International Museum of World War II in Natick, to reflect on the significance of the operation, known as Operation Dynamo.

Q. How did so many Allied soldiers become trapped in the first place?

A. The Germans brilliantly trapped the British and French armies by attacking in the south, causing them to all move in that direction. Another German army, not known to the Allies, then attacked from the north and the combined forces pushed the British and French armies to the coast and quickly forced them into Dunkirk.

Q. Winston Churchill called the operation a “miracle of deliverance.’’ How were the Allies able to pull off this feat?

A. It was a miracle for several reasons: the British soldiers did not give up, peripheral forces continued to hold the Germans back, giving those on the beaches a chance to get out to the boats. A large number of private boats came from England to pick up troops. It was a very combined effort and illustrated Churchill’s statement that “We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender. ...’’

Q. Why is the Dunkirk operation important to the direction of the war in 1940?

A. The importance of Dunkirk was both practical and inspiring. Hundreds of thousands of soldiers got back to England; without them England’s forces were fatally diminished. If they had all been captured it would have been a catastrophic blow and England would have been crippled. If that had happened, Germany could not have been defeated. America had to have England as a staging area to invade occupied Europe.

Q. So it carried huge weight symbolically, as well?

A. It’s the spirit of the effort that stands out, that kept the British alive. All those small private boats that kept coming back to pick up British soldiers. ... In a broader sense, of the entire war, it showed that evil can be defeated if good people come together and act together.

Roy Greene can be reached at roy.greene@globe.com. Follow him on Twitter @roygreene.