The AI is very into putting cities in far away inaccessible places. If you cannot quickly get to the last city, esp. if it is on a one tile island, then you may not be able to take it quickly.
This case of a lone one tile island is possible, but luckily not that likely.
In such case a peace threaty for getting that inaccesable town seems sensible. But it means that occuring flips cannot be undone without declaring war and thus breaking the fresh peace threaty. Also signing the peace in the first place may risk breaking an alliance. So maybe the best course of action is to still keep peace off the table and continue the war till marines.
It would be a war on paper. After 20 turns 1-0.98^20=33.34% of foreign citizens are assimilated and culture flips do also become less likely as the ratio of the global culture values changes in your favour.
After 40 turns 55.43% of foreigners are assimilated and after 60 turns it is 70.24%.
Another option is to delay the end of war. The enemy should keep 1 town on continent and the 1 town on the lone one tile island. When the last military alliance can be cancelled, cancel it and sign a peacy threaty to get the lone one tile island. The former ally still at war with your enemy will then take the last town on the continent. That would be the clean solution.
If the AI is ahead of you in techs, pointy stick research is very valuable and could be well worth starving the cities.
Maybe. But is it is not that expensive to forego such a peacy treaty. There is significant room for interpretation and i prefer to end the war in the first attempt.
If the AI is big, and you are getting hammered by war weariness temporary peace could be well worth starving the cities.
Here it is similar. A few turns of war weariness are an insufficient reason to incur the cost of signing a peace treaty. If however properly ending the war is no option within say 20 turns, then i probably agree.
I do however disagree on starving. Getting slave workers and slave settlers is a better use for the population. Slave settlers donnot flip and they donnot cost any unit support. You do however need to get the needed 30 shields somehow, say by disbanding 3 MedInfs. If you are lucky enough, this may even lure AI into declaring war on you, a preferable outcome if you are ready for it.