Well you just have to assume America would go for the Christian option first, sound legit...
Seriously: I'd love to see a world in which viable laser weapons became the military standard. It would both increase the draw of any given military and end any kind of recruitment issues just by product of the "cool" factor and it would make warfare a lot more "interesting" as a whole. It is harder to hit a moving target with a pinpoint of killing light than one would think, leading the target is no longer really a factor either and wind becomes a serious non-issue. It would take a lot of retraining for current troops but I don't see any really terrible downside.
Well there is the cost, the weight, the maintenance, the required power, the cost again. But besides those valid issue I don't see a single one. Nope.
I'm so oddly for and against this I suppose I'm just ambivalent all over again. I kind of wanna live in pre-end of the world Fallout universe but then again we'd have to annex Canada and get into a ground war with China, and those are really not attractive options in my opinion.