1852 AD
Bomber Base

Our stealth bombers in Hastings have reached the extent of their ability to hit enemy cities. We could move them to Paris and reach most of France, but Paris is full of "smiling" Parisians (pop 22).

It will be much easier to control things in the small city of Dijon. 

1852 AD
Dijon

From Dijon, our stealth bombers can hit almost any city in France. Yet, with a pop of only 10*, it will be much easier to secure. Once the resistance has ended, we should be reasonably sure to hold the small city with just 20-30 units, though we will have many more, just to be sure.  

1868 AD
End of the French

Backed by stealth bombers, German forces take France. The threat to world peace has ended. 

Civilian Control: Many players have trouble controlling the civilian population and will lose significant numbers of military units to city flipping in combat zones. Foremost, keep your armies out of dangerous situations. You need 2-1 dominance, twice that if in resistance, and these are minimum ratios. You may need many more depending on the situation and the proximity to the enemy capital. If you do not have military dominance, then you should park your army outside the city. One reason to garrison in cities is to provide an airbase. Pick a safe location for your bombers, and make sure you have sufficient military control of the situation. Once your bombers re-base, you can reduce the garrison. 

* You should count a resister for every tile that overlaps with another culture. There are 7 overlapping tiles in Dijon, so there are effectively 17 resisters.