Authors:

If you will not fight for right when you can easily win without bloodshed; if you will not fight when your victory will be sure and not too costly; you may come to the moment when you will have to fight with all odds against you and only a precarious chance of survival. There may be even a worse fate, you may have to fight when there is no hope of victory, because it is better to perish than to live as slaves.

Winston Churchill (1986). “The Gathering Storm”, p.312, Houghton Mifflin Harcourt
If you will not fight for right when you can easily win without bloodshed; if you will not fight when your victory will be sure and not too costly; you may come to the moment when you will have to fight with all odds