A proverb conveying that victors are treated as the rightful or legitimate side while losers are labeled rebels — i.e., might makes right; history is written by the victors.
歴史は勝てば官軍、負ければ賊軍という見方で語られがちだ。
History tends to be told from the viewpoint that the victors are right and the losers are wrong.
政治の世界では、勝てば官軍、負ければ賊軍という残酷な現実がある。
In politics there is the harsh reality that winners are deemed legitimate and losers branded as rebels.
裁判の結果次第で評価が変わることもある。勝てば官軍、負ければ賊軍だ。
Evaluations can change depending on the verdict. If you win you're right; if you lose you're wrong.