There is an answer, though. It’s 70% build, 20% write, and 10% fight. Put most energy into building, some energy into writing, and one tenth towards fighting.
Think of the 10% like your defense budget. Your technological progress provides the capital and growth to fund defense. Indeed, you may end up with >10X the resources of the vicious neighboring tribes. Because they focus solely on demonizing others rather than building up themselves. And if so, 10% of your resources will match 100% of theirs.
Then, even by devoting 100% of their energy to fighting, they won’t be able to steal. Your defense is too strong. So they’ll simply need to build their own stuff. As will other tribes. Now everyone gets wealthier, and has less reason to fight.
And this is the upward spiral.