noun
bloodless revolution
A revolution or major political change achieved without violence or bloodshed.
その国では無血革命が成功し、政権が平和的に移行した。
A bloodless revolution succeeded in that country, and power was transferred peacefully.
革命 is a general term for revolution, which may or may not involve violence. 無血革命 specifically emphasizes the absence of bloodshed.
Compound of 無血 (bloodless) and 革命 (revolution).