Yes, Superman was very much in action during WW2. The American propaganda machine found Superman irresistible. Here are some Superman cartoon films made during the war.
Japoteurs (Episode #10, Released: September 18, 1942) is a blatant war-time cartoon featuring Japanese spies as the protagonist and, thus, serve as direct propaganda against the Japanese. On the inaugural flight of the world's largest bomber, Japanese agents steal the plane, and use it to bomb the airfield preventing pursuit planes from taking off. Seeing the disaster, Superman soars up to the plane and finds that Lois Lane has been seized as a hostage for leverage to force Superman to leave the plane. Eventually, Superman saves Lois, and returns to capture the Japanese spies, only the controls have been destroyed and the plane loses altitude. Realizing that he can't fix the situation from inside the plane, Superman grabs Lois. He puts her on the ground, and flies back to slow the descent of the bomber and manages to avoid a crash.Text Source: http://www.supermanhomepage.com/comics/comics.php?topic=articles/supes-war-----------------------
SECRET AGENT (July 1943)
The Plot: Clark Kent helps a Federal agent escape a gang of Nazi saboteurs, and lets himself be captured to learn their plans. He is tied up and taken to their hideout. The agent, a young blonde woman, wants to take information to Washington, D.C. on the largest and most ruthless gang of agents. For six months they thought she was one of them. She has a police escort, but it is attacked. Another group of agents see her drive away. She is trapped on a bridge and nearly crushed in its gears. However Clark frees himself, changes to Superman, traps three of the agents in a lift and saves the agent. He then takes her to Washington.
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JUNGLE DRUMS (March 1943)
The Plot: Deep in the jungle, a tribe of aboriginal warriors is having a celebration. Their leader is a tall man in a white cloak. Secretly, he's really a Nazi commander, and the tribe's sacred temple is really an underground Nazi outpost. The Nazis eagerly await the arrival of an American convoy with information about an Allied attack. When a military plane flies overhead, the Nazis shoot it down. The commander sends the warriors to search for survivors. At the wreck site, the mortally wounded Lieutenant hands his secret documents to the crew's only survivor, Lois Lane. He tells her to destroy the documents. Then he dies.
Lois is caught by the natives and tied up, but frees herself runs into the jungle and avoids capture long enough to hide the documents under a rock. She is then captured and brought back to the temple (outpost) for interrogation where she is tied to a chair. When she refuses to talk, the commander orders the warriors to burn her at the stake. Meanwhile, Clark Kent and another pilot are flying out to meet with Lois's convoy. They spot the wrecked plane not far from the aboriginal village. Clark parachutes down to investigate. Once on the ground, he changes into Superman. He flies to the village. Lois is already being burned at the stake with the commander watching her. Just then, one of the warriors approaches the commander and gives him a set of papers. It's the documents Lois hid in the woods. Overjoyed with success, the commander has his men radio headquarters and send the Nazi U-boats to attack the Allied fleet. Hitler hangs his head in frustration.
Clark arrives and saves Lois from burning to death. When the warriors see a man who can walk through fire, they run in terror. The Nazi soldiers futilely fight back against Superman. Meanwhile, Lois takes a spare white cloak and sneaks in to use the radio. The commander catches her (her ladies shoes aren't well hidden under the cloak), but before he can do anything to stop her, Superman comes to her rescue. She sends a message to the American headquarters, warning them about the Nazi subs. Out at sea, the Nazi subs prepare to decimate the Allied fleet. Before they can attack, they are bombed by a squadron of Allied bombers sent in response to Lois's warnings. The subs are destroyed, and the Allied fleet is saved. Meanwhile In Berlin, Adolf Hitler listens to a newsflash about the defeat of his U-boat force. Angrily, he flips a switch on the radio and hangs his head in frustration as the tune Praise the Lord and Pass the Ammunition plays as the cartoon fades out.
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Destruction Inc. (December 1942)
The Plot: One night in Metropolis, the elderly night watchman from the Metropolis Munitions Works is found dead in a swamp. When news of the incident reaches the city the next morning, Lois Lane and Clark Kent both decide to grab the story for themselves. Clark talks to Lois, not realizing she has gone and he is talking to Louis, who gets angry at what he thinks was a mistake about his name. Lois decides to go undercover at the plant. As she goes to meet with the plant supervisor in the Personal Building, she meets the new night guard, a kindly, white-haired, old man leaving the Personal MGR. Office.
Lois overhears Mr. Jones's plan to blow up the factory. Lois goes undercover as a factory worker. One day, during her shift, she overhears the foreman telling two of the workers that Mr. Jones, one of the supervisors, wants to go over the plan upstairs at 12. During break time, the workers head up to Mr. Jones' office. Lois follows. Up in the office, Lois overhears the workers killed the Watchman and of Mr. Jones' plan to blow up the factory. The switch to the factory's night lights has been rigged to a case of dynamite. When the night guard throws the switch, the whole factory will explode. Just then, Mr. Jones sees Lois outside the office window and opens the blinds, causing Lois to realise she has been seen and run away. He sends the workers to catch her. Lois manages to get away from the workers across a window ledge and beams, but is caught by the foreman who covers her mouth. She is gagged and the workers load her in a test torpedo with another case of dynamite. (As a company rule, test torpoedoes aren't loaded with explosives.) The night guard enters the room and rushes to help Lois.
The foreman stops the night guard by dropping several tons of scrap metal on him. The torpedo with Lois is sent to the testing range and set to be fired at a dummy ship. Back inside the factory, the night guard is struggling to free himself from the rubble. The night guard is really Clark, who has also decided to go undercover. Under the rubble, Clark changes into Superman. As the test torpedo is fired, Clark rushes out to the testing range and saves Lois before the torpedo explodes. He frees her and wakes her, she tells him they are about to blow up the plant. Realizing that they've been discovered, Mr. Jones orders the foreman to throw the night guard's switch now. He reaches the switch, but Superman stops him from throwing it fully.
Just when Mr. Jones thinks his plans are ruined, he spots a truck loaded with dynamite. He steers the truck toward the factory in a collision course, then jumps out before impact. Lois warns Superman, who was previously pinned down by the workers, about the truck. Superman catches the truck and sends it over a cliff, saving the factory. The story ends with Mr. Jones, the foreman and the workers being arrested, and Lois revealing that she knew Clark was the night guard. It may have been meant as a subtle irony that Lois was able to see through this disguise easily but could not figure out that Clark was Superman as well.
------------------The Eleventh Hour (November 1942)
The Plot of The Eleventh Hour: While Clark Kent and Lois Lane are prisoners in wartime Japan, Superman becomes a saboteur. In the Japanese City of Yokohama the Eleventh Hour strikes and a ship is turned over. Superman escapes searchlights while sirens go off and goes through a window, putting a barred grille back in place. Lois asks if Clark is awake, to which he asks who could sleep through a racket like this. Lois says the racket has been happening every night since they have been interned. Clark says it may be sabotage, which Lois also hopes. She wonders if Superman is responsible. A guard tells them to stop talking. A Japanese Official says the sabotage must stop at once. As the Eleventh Hour strikes a Japanese looks at his watch and leaves the window. Superman leaves the same room by removing the grille and drags a ship over into the sea. Sabotage happens every night at the Eleventh Hour, and the Official again says the sabotage must stop. Lois sees Superman as he leaps between buildings. She says outside Clark's room that it is Superman, she just saw him, and the Japanese have a 'swell chance' of catching him. However a guard covers her mouth from behind and drags her out. Notices are put up saying 'Warning! Superman One more act of Sabotage and the American Girl Reporter will be executed at once'. Superman sends another ship into the sea, but is burred under steel girders. Lois is taken out for execution with her hands tied. As Superman digs himself out she walks against the wall and is blindfolded. Superman sees the notice and is fired on, but leaps away. He shields Lois just as the bullets are fired, and leaps away with her. On a ship landing in America Lois is interviewed. She is asked by a Reporter if Clark got away, but says he is still over there but Superman promised to look after him. As the Eleventh Hour strikes in Japan there is another explosion.
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