The movie was pulled from release in the UK after just one week. It was banned there after heated protest from British veterans groups and the military establishment. As the Burma campaign was a predominantly British and Australian operation, the picture was taken as a national insult due to the movie's Americanization of the Burma operation. The resentment that many felt was seen as yet another example of Americans believing they had won the war singlehandedly. It was not shown in Britain again until 1952/1953 and then with an apology disclaimer. Incidentally, writer Lester Cole, who co-wrote the somewhat overly patriotic flag-waving script, would be branded an "Un-American" Communist, becoming one of the Hollywood Ten just a few years later.
All the weapons, uniforms, and gear used in this movie are original and accurate. This was possible due to the fact that these were still in use to the US military when this film was made. WW2 movies made in recent times use reproduction weapons and gear.
The story was partially inspired by "Operation Loincloth," a 1943 long-range operation in Burma by the British Chindits. However, producer Jerry Wald also admitted that much of the screenplay was based on 'Northwest Passage' (Book I -- Rogers' Rangers) (1940), a film about the adventures of a long-range ranger unit during the French & Indian War.
Most of the exteriors of Burma were shot at the Los Angeles County Arboretum and Botanic Garden. The film has an authentic feel to it, thanks to the use of actual military aircraft and materials. Also, the film includes a large amount of authentic footage taken by US Army Signal Corps cameramen in the China-Burma-India theater.
Errol Flynn was criticized for playing heroes in World War II movies. Tony Thomas in his book "Errol Flynn: The Spy Who Never Was" states that Flynn had tried to enlist in every branch of any armed services he could but was rejected as unfit for service on the grounds of his health--he had a heart condition, tuberculosis, malaria and a back problem. Flynn felt he could contribute to America's war effort by appearing in war films, and subsequently made such pictures as Edge of Darkness (1943); Northern Pursuit (1943); Dive Bomber (1941) and Uncertain Glory (1944). Reportedly, Flynn was at his most professional and co-operative he ever was whilst working on Second World War movies. The studios apparently did not diffuse the criticism of Flynn's state-of-health as they wished to keep it quiet for fear of his box-office draw waning.
Gen. Joseph W. Stilwell, aka "Vinegar Joe", was commander of the US forces in the China-Burma-India Theatre and is portrayed in the movie by Erville Alderson, who bears a striking resemblance to Stilwell.
Members of Merrill's Marauders, who were on location as technical advisers, critiqued the fact that Nelson's men killed all the Japanese at the radar station so quickly with none wounded or escaped. That was likely by design because any of the defenders left alive would have to be executed by the special ops troops, something that 1945 audiences would have found objectionable for American troops to do.
One of the minor roles is a character named Negulesco, an in-joke. Director Jean Negulesco was a contract director at Warners who was scheduled to direct Errol Flynn's next picture, Adventures of Don Juan (1948). Unforeseen delays caused it to be postponed and Negulesco was ultimately replaced.
It seems incongruous that after accompanying the platoon the entire way to record the mission, no one in the group seems concerned with preserving or saving the work of Mark Williams, the war correspondent.