Necessary wars are just wars, and the arms of a nation are hallowed when it has no other resource but to fight.
 Niccolò Machiavelli, The Prince (1532). copy citation

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Author Niccolò Machiavelli
Source The Prince
Topic war fight
Date 1532
Language English
Reference
Note Translated by W. K. Marriott
Weblink http://www.gutenberg.org/files/1232/1232-h/1232-h.htm

Context

“In politics there are no perfectly safe courses; prudence consists in choosing the least dangerous ones. Then—to pass to a higher plane—Machiavelli reiterates that, although crimes may win an empire, they do not win glory. Necessary wars are just wars, and the arms of a nation are hallowed when it has no other resource but to fight. It is the cry of a far later day than Machiavelli's that government should be elevated into a living moral force, capable of inspiring the people with a just recognition of the fundamental principles of society; to this "high argument" "The Prince" contributes but little.” source