I continue to urge peace. Even an unjust peace is better than the most just of wars against one’s countrymen.

[Equidem ad pacem hortari non desino; quae vel iniusta utilior est quam iustissimum bellum cum civibus.]

Marcus Tullius Cicero (106-43 BC) Roman orator, statesman, philosopher

Epistulae ad Atticum [Letters to Atticus], Book 7, Letter 14, sec. 3 (7.14.3) (49 BC) [tr. Shackleton Bailey (1968), # 138]
    (Source)

See also this letter from 46 BC.(Source (Latin)). Alternate translations:

For my part, I never cease urging peace, which, however unfair, is better than the justest war in the world.
[tr. Shuckburgh (1900), #309]

As for me, I cease not to advocate peace. It may be on unjust terms, but even so it is more expedient than the justest of civil wars.
[tr. Winstedt (Loeb) (1913)]