When history looks back I want people to know the Nazis weren't able to kill millions of people and get away with it,

When history looks back, I want people to know that the Nazis could not kill millions of people with impunity.

When history looks back,

A BLACK MARK ON U.S. HISTORY

If you know from history the danger, then part of the danger is over because it may not take you by surprise as it did your ancestors.

Should history repeat itself, my example will repeat itself too...and not once, but fifty-fold.