Reading this thread reminded me of something sort of unpleasant, which in a moment of schadefruende, I'll share will all of you regarding the "realities" of warfare at TL15:
One of the biggest "stupidities" of (many) in the New Era Traveller had nothing to do with Reformation Coalition, the Virus, or the Wilds.
It was the Regency Marine Corps.
I don't think I really could think of a force with a mission more idiotic. They're apparently the TL15 force of some that was called in when the "gloves were off" and without any kind of light touch (which is what the Regency Army was stuck doing - all the unglamorous duties like counter-insurgency). I really didn't understand what kind of 15-year old boy thought up of their mission and weapons, but they had the typical TL15 grav belts, battle dress, and fusion guns, their tanks had even bigger fusion and were backed up with battlefield meson guns and all this other stuff and would just blaze away and destroy everything like some "Superforce" at TL15 commanded by Archduke Norris' lesser-known cousin, Chuck Norris.
The problem with the force was (and is for me) ... what's the point? Just disband them.
If you're just going to indiscriminately destroy your enemy without much regard for the lighter touch (which I identify as minimizing civilian causalities and destruction of property) why do you need ground troops at all? If Marines are practicing such callous destruction, with each one armed with some hand-held fusion weapon that can "level a building in a single shot" (and apparently not carrying lighter because that'd be the realm of the "wimpy" army). I don't see the point of such forces on the Imperial level besides it being some archaic soldierthink on the part of GDW's writers in some unholy union with the He-Man warrior fantasies of drooling gearheads - who needs an force of lotharios armed with weapons like that?
Just get the Navy's more powerful orbital batteries to just pound the offending areas to atomic (or subatomic) pieces using the superweapon of the day, anti-matter, Meson Guns, fusion bombs, megatons of water ice dropped from orbit, whatever. The resolution of sensors at TL15 would certainly allow starships to hit even small groups of people on the ground with whatever superweapon you want to hit them with. It'd just be that video we all saw of the AC-130 blowing the tar out of those guys on the ground in a display that was so "unfair" to me that "terrorists" or "insurgents" or not, I actually felt sorry for those guys.
Once the Navy's done pounding all the obvious and suspected forces of resistance (including I'm sure countless "innocent" people, but that's war, right?), land the Army to garrison the planet and mop up residual resistance and call the job a good one. Yeah, it's not as fun for the players, but I think that'd be "all out" war at that Tech Level.
Now, I think the Army's mission would be a lot more interesting at TL15 with a dilemma we understand today: "Conventional Forces in the age of Nuclear Weapons." Same with "low-intensity" forces in Traveller I think - they have these meson guns and such, but due to the collateral damage, they couldn't use them.