As an Alabamian, I can tell you that if it saves U.S. lives, buy it...from here, from there, wherever. Our economy here in Alabama will be just fine. Take care of our troops, first.
Now, with that said; slat armor is just metal. Steel-workers in Canada, Russia, Alabama, Japan, China, wherever...can all make it competitively. The price difference is *not* large. On days when the U.S. Dollar drops, Alabama steel is often the world's cheapest, in fact.