Consider the potential defense a swarm of drones equipped with various countermeasures could be against those missiles. They could be deployed quickly from a ground station or any cargo vehicle; possibly even from an eighteen wheeler if they were made small enough, and certainly something like a C-130 as someone else pointed out. I'm not clear on the effectiveness of anti-missle systems like the Iron Dome but I doubt there's anything that could to that kind of air defense from a platform that mobile and of such a small form-factor. You could even use a tower as a station in an urban setting and just drop them out the windows and crank up the engines midair. You could have an air-defense tower every few blocks.
It might seem minor but shifts like this have the potential to give one combatant a meaningful edge against an opponent lacking the same capabilities. Imo, even as a purely defensive tool this will allow much smaller entities to maintain control over their space against aggressive neighbors. Miniaturization of computers and automated weaponry reduces the space/resource requirements to maintain a state-like monopoly on violence within that space. I see this all as being firmly in the same trend as the increasing availability and power of biological engineering equipment and techniques and the increasing risk posed by locally-embodied/concerned AGI. These all have wildly varying threat profiles and difficulties with determining likely timelines but you get my point.
I never even got into possible offensive uses of these drones but one of my nightmares is matroska drones, C-130, to these (which can deal with other airforces and large ground forces,) to hunt-and-kill quadracopters to little single-serving shaped-charge drones. You can't nuke a city because of insurmountable optics but enough people were able to stomach large-lascale bombing of cities within the last 20 years that I would not be surprised at all if this kind of force was used to neutralize a city by bringing to fruition the promise of "precise bombing" and actually only killing the people and destroying the structures you mean to. It's a brand new WMD.
And even if I'm totally off base this is great sci-fi.
Edit: Bullshit punctuation to trim one word (and then add this note and actually make it a good deal longer, nice.)