Both Jews, and Muslims are sympathetic to this view. Christians wish you would “kill it with kindness,” but that didn’t stop them from starting the Crusades, which, incidentally, weren’t about self-preservation but rather reclaiming that which was God’s.
The Hebrew Bible contains many incidences of God condoning what we might consider selfishness, but stopping short where it actually hurts others. For instance, God was fine with David taking dozens of wives and Solomon taking hundreds, but when David decided to kill a woman’s husband in order to take her for himself, He rebuked David by killing his firstborn by that wife.
Note that Jesus’s ‘turn the other cheek’ was applied to an insult, not a threat. When things threatened God, Jesus wasn’t so nice, turning over the tables in the temple of God and kicking out all the merchants.
If the thing you’re trying to protect yourself from merely assaults your pride or things that aren’t really all that important, consider turning the other cheek once or twice and see what happens. If it doesn’t work, after all, you aren’t Jesus, try something else. We’re all here to learn, after all, and the best way to learn is by making mistakes.