I have waited to answer this. There are only a few basic principles in my style. But they are present in everything we do.
A few of the principles and concepts are: 1) Re-direct, Distract, Off-balance 2) Intercept the attack and control the attacker immediately 3) Do not back up, unless you have no other choice 4) Respond to an attack, rather than to react to it 5) If you tense up you give the attacker feedback, as well as limit your speed 6) Always keep your shoulders relaxed and do not raise them 7) All attacks regardless of style can be analyzed using only 12 principles. Response to the attacker can be any technique that uses one or more of the 12 principles to defeat the principles the attacker is using. (12 principles in no particular order : Line, Power, Tree, Rooted Tree, Water, Tiger, Tiger to Balance, Tiger to movement, Circle, Half-Circle, Evasion, Hidden movement) 8) If a "hard fist" technique fails, use a "soft fist" technique.
In other words if a strike, kick, ...etc. fails, Immediately execute a lock, throw, ...etc. If a "soft fist" technique fails, immediately execute a "hard fist" technique. 9) All joint locks either root the attacker, or up root him 10) Balance is important, but position is always more important in that if you are out of range, it does not matter if your balance is good, you can't do anything to the attacker. 11) Once you get within range, do not move out of range or allow the attacker to do so.
As per your example, I am studying Shurite Karate Jitsu. Through my understanding of our art and the other martial arts I have studied over the years, I cannot define a SINGLE core principle; or even a small group. To me the one that would be defined would then be broken up, or be felt as though it was missing other components, and therefore incomplete.
Attempting to make this a broad core principle, I would say that you may be on to something with body movement. "To understand how to seize, and defeat the opponent efficiently, with as little effort as possible." Spatial awareness is one of the biggest elements taught at my dojo; which also incorporates position, touch sensitivity, and balance as well.
Making that simple statement, causes my brain to fry over the fact that I am leaving so much out. Honestly, to me this question would have been much easier to answer 15 or more years ago, because I knew less. I believe that the lines blur the more we learn, especially when it comes with making distinct claims about a singular principle being the driving force behind any martial art.
Now, when talking about a specific technique, I can easily break down the core principle or principles, but that's a different story. When I think about myself and my art, do I believe that I am performing it?... Everyday. I live my art, resting, working, going to school, and of course when I am training.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.