conflict
A universal aspect of any given human culture is the accepted method by which disputes and disagreements between individuals are resolved. Some methods that have been considered acceptable at various times in various places include (a) engaging in violent physical combat, (b) challenging one's enemy to a shooting duel, or (c) appealing to a higher administrative religious and / or legal authority to decide a case. These successively less violent methods of dispute resolution required thousands of years of iterative development and piecemeal improvement. What is common to all of them, however, is that the outcome of the process is deemed legitimate by all sides prior to engagement. In other words, everyone agrees on what "winning fair and square" means. Everyone agrees on what "cheating" means. If not, the process is void of binding authority and might as well cease to exist.
Extrapolating from this observation, we can infer that aggregate conflict functions in much the same way as interpersonal conflict. The aggregate version of violent combat is called war; the aggregate version of administrative deliberation is called politics. The same conditions hold in aggregate terms: all sides must accept the outcome of the process in order for it to be deemed universally legitimate. If this ceases to be the case for any reason, the process becomes irrelevant, and a new process must be forged if one wishes to avoid the breakout of Hobbesian total war.
Humans will continue to see things differently from one another and engage in conflict until the end of time. All eschatological texts allude to the fact that a post-conflict era is also a post-human era. Conflict is an integral part of the human condition; to reject this is to fall into the trap of utopian thinking.