During the first Anglo-Sikh war, there were allegations that the commanders of the Sikh Army, looking to preserve the rule of their leader, decided to deliberately destroy the Khalsa (the "Pure"), the heavily modernized Sikh army, by mismaneuvering it in an ill-advised conflict against the British, as they felt it was an internal threat. However, this claim should be viewed with skepticism as it is advocated by Sikh historians who obviously have a vested interest in making the Khalsa seem it was defeated not in a clash of arms but by treachery.
Shaka Zulu, in 19th-century South Africa, once supposedly ordered an Impi (a formation of soldiers) to march over a cliff, in order to demonstrate the loyalty and discipline of his troops. I haven't found a source on it, but it's a well known part of his legend.
The First Sikh War (1845-6) could be interpreted this way from the point of view of the Sikhs. The Sikhs were essentially forced to war with Britain by the over-powerful military faction, and as such the ruling Sikh nobility likely hoped that, if Britain could not be defeated, that their own military would be crippled in the process. As such, there is correspondence between the Sikh commanders and the British assuring that they were loyal to the Empire. At the crucial Battle of Ferozeshah, one Sikh noble did not send his army to attack when the British were very vulnerable; one suggestion was that in fact he did not want to defeat the British, and preferred to watch his allies be crushed.
Maybe closest to what you're looking for, but on a smaller scale, is the story of Tibor Rubin. He was a Jewish soldier who fought for America in the Korean war (1950-3),whose heroic actions got him a retrospective Medal of Honour. He fought bravely in many desperate situations, but often the reason why he was in the situations in the first place was that his sergeant, a raging anti-Semite, hated him and would 'volunteer' him for suicidal missions.
These are just off the top of my head, I'm sure there are plenty of other examples
Unfortunately, your question breaks our rule against "throughout history" questions, found here. However, something like this would be a fine topic to submit for Tuesday Trivia (message mod /u/caffarelli) or possibly Monday Mysteries (message mod /u/Celebreth). If you can't wait that long, you can ask again in our Friday Free-for-All thread, which should be stickied to the top of the subreddit today at 11 a.m. EST.
Thank you for your understanding.