To avoid detail in the name of getting at the underlying question, I've got a modern-adjacent military being invaded by well-equipped nomads supported by angry aliens in space who have far too many nuclear missiles for anyone's good, but very little manpower. The protagonists' air force is intercepting most of the warheads, but not all of them. Neither the protagonists nor the nomads have their own nuclear arms.
This war was a shock to people, but they had hours before the initial strike, and an alien attack like this has been THE thing people have been paranoid about for centuries, so they would have a plan of action if this kind of war happened, as it has.
I want to know what a planetary military in this kind of situation might do to avoid being nuked as it fights on the ground.
After reading far too much about the Pentomic Army, and why it's a very bad idea to spread out to the point nukes are ineffective if you are trying to fight a conventional war at the same time, I need some better ideas to throw at the wall of plot relevance. I'll settle for directions to the people who've been throwing stuff at this kind of wall for the last seventy years.
If you have too, just suspend your disbelief that people would continue fighting after the atomic bombs began to hit. I believe it is more interesting if they did.