I believe the answer to this is "true." Really, all conclusions on all events are subjective. But considering history, conclusions on events are especially prone to subjectivity. Consider who writes the history books. If one country wins a war against another country, they will write about themselves as the noble party and portray the enemy as villainous. However, this may not be the real case. This occurs much more than we think, and we must research different events to make sure we are not blindly buying into what people say. Hope this helps.