L. Neil Smith says:

For those uninitiated in the ways of libertarians, the acronym "ZAP" stands for "Zero Aggression Principle", a slightly different term some of us have settled on lately for what the movement has long called the "Non-Aggression Principle". What it says is that nobody has any right to initiate physical force against anybody else, for any reason.</p>

Skipping over a lot of nitpicking that goes on among libertarians about formulation and implementation, what it means is that we're not pacifists. We will fight, we just won't start it. And if everybody acted that way—not starting it—about 90 percent of the world's problems, give or take the occasional volcano or tsunami—would be solved. I changed the name simply because I thought that the acronym "ZAP" was a lot more dynamic and attractive than the more traditional "NAP".

One of the best and, to me, most interesting features of the Zero Aggression Principle is that so many different folks arrive at it from so many different angles. I'm not sure where it came from originally. I first read of it in Ayn Rand's essays, but later heard it explained in greater detail by Robert LeFevre. Other teachers have taught it, as well.

In Independence Day, Will Smith puts it in terms his character might well have learned from his mom: "Don't start nothin', won't be nothin'!"</blockquote>