I've read much about Augustus' placement of veteran colonies in places like Antioch in Pisidia. There was clearly an intent to use the placement of these colonies for regional defence and pacification. I have found much on the social organisation of the colonies, and their role in providing army recruits.
I can find little on how the colonies were defended. Were they simply reliant on the nearest Roman army units? Did they have army cohorts stationed at them? Or did they also maintain their own militias both for self defence and for the training of young men for later army service?
Advice on any academic papers on this subject would be appreciated. Thanks