(Next Big Future blog)
Well, judging by the illustrations known, "Fighter planes" is not exactly accurate. It's more like bombers and gunships; I remember concept drawings about such intents from the 80's.
100 kW laser output has been considered the threshold for an effective destructive* combat laser for a while; a 150 kW laser would be effective against a wide range of targets. That is, unless said targets employ countermeasures.
Destructive combat lasers would force lots of thoughts and lots of new dynamics onto the tactical level and also onto measures-countermeasures spirals in military tech R&D and procurement.
To be honest; I'm not particularly interested in destructive lasers.
The attention and thought they would attract would divert from addressing more fundamental and less sexy problems in military theory and security policy. I can already imagine the voices which will claim that the force with the better lasers will dominate the battlefield. *Sigh*
*: I wrote this to point out the difference to lasers for ranging, beam rider guidances, illumination, obstacle detection, 3D sensor functions and dazzling..