Laser beam visibility in atmosphere

I’m working on a science fiction story and would like to introduce lasers as a weapon. I’ve read a bit about the effect of very high energy breams in air and it is hard to get a definitive story. With a MW beam presumably any dust is vaporized and perhaps the atmosphere ionized. Does this affect propagation? What would it look like? Of course for visual impact one would like the beam to be visible. Again, what I find on the internet is ambiguous. I’ve seen a picture of a nice bright beam but it is not clear if this was enhanced by dust or not. In a dusty battlefield with lots of burning debris would this be game over for a laser weapon or could it punch through? How far through?

Any guidance appreciated.