That is very true as well. Truth as Sentryduty says is subjective, however the farther we get from a conflict the less emotionally tied we are to it.
The thing I like about the farther we get from the conflict is the less people feel the need to try and justify it. Information which was hidden becomes available allowing us to reanalyze what happened and understand it from both sides (or more depending on how many sides were involved). For me roughly WWI and earlier is the area where we are mostly able to debate without emotion as it is now more or less outside of living memory. It is also partly why I have switched my main focus to WWI because I can actually hold debates with people which aren't emotionally charged (I also just find the era fascinating).
On the other hand WWII and Vietnam are still much to recent to debate with people, as there is still a fair bit of emotional baggage involved with those conflicts. It is hard to look at things in a unbiased manner when people are insistent there perspective is correct without any information to back it up (not saying it isn't correct, they just aren't willing to even consider it from another view point).
Its like I tell people, to go find their truth. To listen to what people have to say and figure out what is right and wrong to them. Most people just aren't willing to do that however as it is much easier to just listen to what others tell you.