This is one of THE BEST episodes of the Outer Limits. The story demonstrated the moral perfectly.
*** SPOILER ALERT ***
@Robert Wieneke
The Human General ordered his ship to escape and not to return fire. Unfortunately they disobeyed, returned fire, destroyed the Dreg carrier and were themselves destroyed. Had the Human ship left, they would not have been destroyed.
The Dreg Admiral had no way of knowing that the Dreg shuttle crash was an accident. From his perspective, the Humans shot down the shuttle, captured his people, tortured them for the codes, and then sent the stand down signals to trick his fleet. At some predetermined time, the Humans would simply ambush the Dreg as they turned around to go back.
Since both high commanders had their guns at each others heads and the finger on the trigger, the Diplomat had to convince the Dreg Admiral to stand down. If the Admiral shot, the Humans would retaliate and then - annihilation.
Since no Dreg was alive to prove that peace had been agreed upon, she had to prove something else. She proved that under no circumstances would she be able to benefit if the Humans ambushed the Dregs. She gave up everything she had, to prove that her words were true.
Because a liar would only lie if she could benefit somehow Read up on the parable of King Solomon, the two mothers and their infant child. This is an old story reworked, and retold with a modern twist.