But the nuclear walls we currently have in place function to make daily contact with war a reality for the lowest % of human population in history.

I agree with you on that. On the other hand, I doubt that 100% of humans were ever directly involved in warfare. As you point out, war has been reduced by the "nuclear wall" which is why I think nuclear weapons are actually one of the single most effective instruments of peace, not war. However, while nukes are a major deterrent of war, they do not reduce our passions, our collective desire for power and conflict. These are the seeds that start war and they are present in all of us, from the liberal, peacenik professors at our colleges to the guy installing your roof listening to Rush Limbaugh. Warfare from the beginning of time has always been a wager, a balance between the perceived cost and the perceived benefit and whether a nation, tribe, whatever, thinks they can win. War hasn't been reduced because we are becoming more civilized, it has been reduced by your nuclear wall and a single dominant military, cultural and economic superpower. A good example is that WWI and WWII didn't happen all that long ago and the world was ready for WII only 21 years after the carnage of WWI, we will always have the taste for war because the things that drive us to war remain the same as ever, the odds have just made major wars a bad wager in most cases. War has only evolved to suit the current global environment, it has evolved into small, guerrilla wars where nuclear retaliation, even massive conventional retaliation would appear disproportionate. These small guerilla wars have not happened by accident, they have been left by a natural selection of sort, that is to say they are the only types of wars that "work" currently. If nuclear war worked right now in that it could allow one nation or group to gain a strategic or economic objective it would be used just the same. The goal of every war is to achieve some sort of objective(s) with as little casualties as possible on all sides, even Hitler would have aimed to take the USSR bloodlessly if it was possible, even he wanted to achieve goals first, not needless killing. Although, if the US falls, or retracts from its role as superpower, there will be a power struggle to take our place and we may see some larger conflicts.