Apologies if this is the wrong site, I didn't know whether to post this question on literature or history or here.
The title says all. A book cited verbatim this quote by Leon Gambetta without a translation.
La souveraineté du but
As requested by @anonymous2 I'll add some context.
Once embarked upon a war, England has always ruthlessly devoted all means at her disposal to its prosecution. English policy was always guided by what Gambetta called "la souveraineté du but."