The hardest parts are still power source, bloom on target (burning stuff kicks up dust into the air and disperses the laser), and adaptive optic focusing to get

The hardest parts are still power source, bloom on target (burning stuff kicks up dust into the air and disperses the laser), and adaptive optic focusing to get through all sorts of atmospheric conditions. It must be said that the last two are in the realm of things the US military might plausibly be decades ahead on, in secret. The power source on the other hand is far more likely to emerge from the public or academic sector.