"an unavoidable requirement" is correct and usable in written English.
It is typically used to refer to something that must be done even though it is difficult or unpleasant. For example: "Filing tax returns is an unavoidable requirement for anyone who earns an income."
As collaborations and their context are now fast evolving, agility of collaborative workflows is now an unavoidable requirement.
That's an unavoidable requirement; allowing those who oppose the death penalty to serve on such juries would guarantee that the penalty could never be imposed.
There is no escaping the need to build systems that reach all women, and provide access to known interventions that will benefit women's nutrition: both for its own sake, and as an unavoidable requirement in the first 500 days of life.
Men, who are accustomed to having women deal most fully with the consequences of that unavoidable requirement, may be more able to see it as less limiting.
We speculate that these similarities among distantly related taxa are due to shared, unavoidable requirements for pathogen resistance, and potentially biomechanical stability.
From the above arguments, I conclude that, even if inbreeding is not immediately advantageous, it is an absolute requirement, an unavoidable price to pay, for long term survival of the descendants.
Thus, The Ethics of Ambiguity provides an analysis of our existential-ethical situation that joins a hard-headed realism (violence is an unavoidable fact of our condition) with demanding requirements.
Rather, as we have seen, Kant holds that it is an unavoidable feature of human reasoning, instead of a moral requirement, that we represent all particular duties as leading toward the promotion of the highest good.
Since there were only 22 children with AML in our study, an unavoidable consequence of the rarity of the disease and the requirement for obtaining blood samples from very young children, our results cannot be considered as conclusive.
Brown is an unavoidable subject.
This is an unavoidable tightrope.
