What is needed for a conflict to be solved?

What is needed for a conflict to be solved? Those who communicate on behalf of the parties involved should be competent, authorised and acknowledged to be able to settle the conflict? To find out how many parties actually are involved in the conflict and their measure of involment? Should the parties come to terms on the main definitions, estimations for the causes of a conflict at least? Should the parties identify honestly which unjust actions, mistakes were committed by all the parties involved? ... .. .