Neal Earhart wrote:
"The Art of Peace is the principle of nonresistance. Because it is nonresistant, it is victorious from the beginning. Those with evil intentions or contentious thoughts are instantly vanquished. The Art of Peace is invincible because it contends with nothing"
- O Sensei
When you are attacked by someone if you resist the attack then you are not at peace within yourself nor is your attacker at peace within themselves. Nonresistance is not resisting the attack but removing oneself from the attack, aligning yourself with your attacker's direction of attack, taking control and redirecting the attack to neutralize it in your favor.
You are at peace from the beginning of the attack because you know how to protect yourself and you demonstrate this peace to your attacker through your technique.
You win because you are at peace and he isn't.
The Art of Peace is invincible because you have moved out of the line of attack and there is nothing to continue the attack against.
You learn this not by theory but by practice.
You practice for when you will be attacked but pray that you never will be attacked.