“Remember this central truth. Your enemy is there because he, too, has weighed the consequences of failure and accepts them. Play always to win, because nothing else matters”

Variant: Always forgive your enemies — nothing annoys them so much.

Pastwatch: The Redemption of Christopher Columbus (1996)

Please read this article for more information: Did Camus ever say “Always go too far, because that's where you'll find the truth”? | Literature Stack Exchange https://literature.stackexchange.com/q/16662/1015
Misattributed

from the vantage point of the enemies
Churchman had identified four generic enemies: politics, morality, religion, and aesthetics.
Source: 1960s - 1970s, The Systems Approach and Its Enemies (1979), p. 24; Partly as cited in: Reynolds, Martin (2003). "Social and Ecological Responsibility: A Critical Systemic Perspective." In: Critical Management Studies Conference 'Critique and Inclusively: Opening the Agenda'; in the stream OR/Systems Thinking for Social Improvement, 7-9 July 2003, Lancaster University, UK.

Source: Frost Burned

Karl, Ch. 26, Sam Loyd's Challenge
The Emperor of Ocean Park (2002)

OSCON 2002
Context: It's insane. It's extreme. It's controlled by political interests. It has no justification in the traditional values that justify legal regulation. And we've done nothing about it. We're bigger than they are. We've got rights on our side. And we've done nothing about it. We let them control this debate. Here's the refrain that leads to this: They win because we've done nothing to stop it.

Thus It Is, 1989, p. 164
As of a Trumpet, On Eagle's Wings, Thus It Is

Source: Gone Girl