The Boy Commandos was a hugely successful Golden Age comic book feature, and no small reason was its extremely timely setting. Joe Simon and Jack Kirby made their bones on Captain America for Martin Goodman's outfit, but were seeking a better deal and so contracted with DC. What made Captain America stand out was the unusual confluence of real world events and a viscerally patriotic hero who for the most part battled spies and other criminals in the United States. With the Boy Commando, Simon and Kirby take the battle to the Axis powers with a rough and tumble team of tyros.
At Marvel Simon and Kirby had concocted the Young Allies which had Bucky and Toro ally themselves with regular kids to battle such enemies as the Red Skull. They took that formula and introduced an international team of youngsters who rushed into battle alongside the toughest soldiers, commandos who spearheaded the battle against Hitler, Mussolini and Tojo. Andre Chavard is French, Alfie Twidgett is British, Jan Hasaan is Dutch and Brooklyn (no last name) is of course American. These four youngsters served as mascots of a sort, similar to Bucky, but were often on the battlefield across the globe. Their leader is Rip Carter, a sharp-chined classic good guy and all around role model for the boys.
The key to the success of the series was that as interesting as these characters might have been, they were often not the focus of the stories. Very much like Will Eisner's The Spirit, the stories of the Boy Commandos often focused on one-shot characters who demonstrated unusual bravery or cowardice or both. Very often the Commandos themselves would disappear in their own feature, showing up at the end to tie up the loose ends. This gave the stories a real variety and also downplayed the fundamental weakness of the series, the improbability that boys could effectively fight with such gusto on the war front. The stories wind across the globe, hitting all the theaters of war and invariably offered up a patriotic message of support and encouragement.
The Boy Commandos were very much a product of the times and captured the zeitgeist of the country. Simon and Kirby, who both served in the war effort (Simon in the Coast Guard and Kirby overseas under the command of Patton) really seemed to have a sense of what the moment required. They also reveled in the storytelling of comics, clearly to my eye adapting many of the popular tropes of movies to the comic book page, another similarity to Eisner's work. But where Eisner tapped into the film noir aspect of movies, Simon and Kirby seemed to really love comedies and adventures. When I read the dialogue of Brooklyn, I hear the voice of Curly of the Three Stooges ringing in my head. Whatever the elements of the brew were, it's clear that Simon and Kirby and the members of their studio were pushing the limits of the medium and having fun doing it.