There might well be other factors—offhand I can think of setting a precedent for “negotiating” after an invasion, and gaining a stable advantage from having the territory (so the loss of the army during the invasion will have been worth it).
Depends on what’s on that 1% of the territory, and whether it allows me to take over the entire country in the future, for example. (I do hope Putin will lose 90% of his army at some point.)
If the percentage of land the invaders get for each attack is low, and the cost of an attack is high, you are not encouraging them that much.
There might well be other factors—offhand I can think of setting a precedent for “negotiating” after an invasion, and gaining a stable advantage from having the territory (so the loss of the army during the invasion will have been worth it).
Numbers matter. Losing 90% of your army to gain 1% territory does not seem worth it.
Depends on what’s on that 1% of the territory, and whether it allows me to take over the entire country in the future, for example. (I do hope Putin will lose 90% of his army at some point.)