The Way Ahead is an inspiring war film starring David Niven showing how disparate civilians came together to work as a British Army fighting unit. It was written by Eric Ambler and Peter Ustinov and directed by Carol Reed, who together had created a similar 44-minute training film in 1943. The Way Ahead was an expanded remake of that earlier film.
Niven’s autobiography said that the film was shown for many years for training at the British Army’s officer training school where he had graduated in 1930. It’s that good, in fact all of the top 25 in the Internet Archive Top 100 are Leonard Maltin-rated 3½ (of 4) stars or better.