I'd have to say that conflict is not futile. We learn so much through conflict that we wouldn't learn any other way. For example, internal conflicts can shape and mold us in a way that nothing else can. We learn about ourselves and our beliefs through external conflict. Of course, not all conflict is necessary. Sometimes it seems that nothing is accomplished by conflict. However, we always learn through each conflict we see or we are involved in. I don't think conflict could be removed from the human equation completely. We would all like to see less wars and other major conflicts. We would all like to see more peace and more people getting along, but that doesn't mean that all conflict is futile.
In all seriousness, #2 makes the excellent point that some conflicts are not only necessary but noble, or even moral. The U.S. had the moral responsibility to abolish slavery when it became obvious to most people that the "science" of race-based discrimination was incorrect. While this may seem like a no-brainer today, remember that slavery -- for a myriad of reasons -- has existed throughout recorded history. Many slave nations considered the slave to be simply an indentured servant, one who could work off his debt and be free. Others based their slavery on attitudes of superiority and assigned the slave a property value. In the end, we grew to the understanding -- based in real, objective science -- that all men are truly born equal, and therefore there cannot be a moral argument for slavery. In that sense, the conflict between those who wanted freedom and those who wanted to keep other races down was absolutely moral and the very opposite of futile.
This is a great question. You can be sure that there will be many opinions out there. In my opinion, most conflict is unnecessary and it causes so much damage. However, not all conflict is futile. There are some cases where conflict is necessary. Here is one cases where conflict is necessary.
There are times when you need to defend yourself, or others, or even your nation in the face of evil. Under these circumstances, you will need conflict, even if it means war. For example, most peole will say that the opposition to Hitler was necessary. The alternative would be unthinkable. Similarly, most people would say that the conflict to abolish slavery was a noble one.