In many Sci-Fi settings, there are planetary assaults. Common ideas among sci fi fiction include landing ground forces, orbital bombardment, and blowing up planets.
Suppose in one of these settings, faction A landed troops and defeated the conventional militaries of the Faction B and started an occupying force on several planets. This had gone on for three generations, however despite the entire land being nominally held by faction A, in some places low scale conflict like sabotage, hostage taking, and shooting happens. Sometimes colonists and administrators of faction A are killed.
If destruction of the rebellious population was desired, an easy way would be to just evacuate all of Faction A’s personel and then just glass the planet with several push of buttons.
A commander of Faction A analyzes the situation and determined that sympathy for Faction B had fallen to an all-time low. Committing atrocities against people who were sympathetic to them would result in
negligible interstellar political consequences and would in fact increase internal support among Faction A. The commander then analyzes the situations and tries to determine which settlements are salvagable.
In most of the occupied planets, he orders a continuation of the occupation forces to do what they were already doing. Work with local police to find troublemakers before they cause trouble and if trouble does come up, respond with military force.
In some planets he orders restrictions of passage to and from the planet and between urban centers of it.
On one planet, he orders the evacuation of all non-military personnel of Faction A. He has local authorities come up with a list of thousands of loyalists. The loyalists, anyone vouched for by the loyalists, anyone vouched for by those people, and anyone vouched for by the guys who were vouched for by the loyalists are evacuated too. Then military personnel are ordered to kill every sapient being on the planet besides Faction A military personnel. Any neutrals are assumed to be enemies masquerading as civilians. Unlike most of the other planets where the occupation force continues to try to seperate guerillas from civilians and everyone is presumed innocent unless proven guilty, here the force no longer attempts to differentiate and will assume all loyalists are evacuated. If it thinks and moves, make it dead. However, the planet’s ecology is desired to be kept as close to intact as possible. That means no orbital bombardment, no nuclear weapons, no WMDs of any kind. Artillery and conventional bombardment is fine. Burning down a whole forest is not, but burning several acres to smoke out a single guerilla is.
Assuming the commander is correct that there are no interstellar political consequences between Faction A and other factions like Faction C, D, and E and that he was correct that internally his own troops would be like “finally!” isntead of “we have to do what?” does this make the job of the military easier or harder? Let’s just restrict ourselves to the case of the planet where the occupation force became an extermination force and not the planets where the occupation force was ordered to continue. Does this army’s job become easier?