Mitsuo Fuchida, the captain that lead the attack on Pearl Harbor, later became a Christian and settled in the US permanently.
Felice Benuzzi was a P.O.W. in Kenya during WWII. He recruited two others to stage an escape so that he could climb the second highest peak in Africa, knowing that there was no chance of a permanent escape. With scant food and only improvised equipment such as barbed wire crampons, no porters or guns, they traversed the jungle, encountering wild animals, and climb the mountain. Two of them reached a point ~5000 m high on the 5199 m mountain. And then they returned and broke back into the camp, as planned. He later wrote the book based on this, which was made into a fictionalized movie.
A Japanese Oil Tanker captain fell into a cactus at a Santa Barbara Oil Field, provoking laughter from the local workers. 5 years later he returned in an Imperial Japanese Navy sub and made the first mainland shelling of the US at that oil field.
The US considered dyeing Mt. Fuji black in WWII as psychological warfare against the Japanese.
Witold Pilecki, a Polish Army officer, volunteered to get imprisoned in Auschwitz to gather intelligence and escape.
Part of the reason why the Allied secret services could fool the Nazis many times is that the deputy head of the German Abwehr, Hans Oster, actively sabotaged the Nazi war effort.
Rationing in the United Kingdom during WWII actually increased life expectancy in the country, and decreased infant mortality. This was because all people were required to consume a varied diet. The only negative results being the increased time needed for meals to consume the necessary calories from bread and potatoes, and what they described as a “remarkable” increase in flatulence from the high amount of starch in the diet. The scientists also noted that their faeces had increased by 250% in volume.
During World War II a Soviet pilot was shot down while returning from a reconnaissance mission and hid in the woods nearby. When a German fighter pilot landed nearby and got out to investigate, the Soviet pilot rushed out, stole his plane and flew home, barely avoiding being shot down by Soviet fighters in the process.
In 1944, Lt Leon Crane bailed out of a malfunctioning plane, survived in Alaskan wilderness for 81 days, and walked 120 miles to safety.
The last WW2 POW to be repatriated was a Hungarian soldier who sat in a Russian mental hospital for 53 years before a linguist realized that he wasn’t actually talking gibberish.