Not sure how up to date it actually is, but from the Main Menu, go to HELP, then look down to GAME PLAY then under than read everything under STRATEGIC TARGETS.
What I think you are getting at is the downtime listed, and how long things actually stay down. You have to take into consideration the drone convoy resupplies, as well as player resupply runs.
Cities resupply HQ and strat factories, and other cities on large maps, IIRC.
Strat factories resupply Field, Base, and Port strats.
A City has a down time of 3 hours, but...
Each drop of convoy or train supplies on damaged city targets reduces the 3 hour downtime by 30 minutes. Each drop of player supplies reduces the downtime by 15 minutes.
Those convoys spawn every 10-15 minutes along their routes. If the supplier is damaged below 50%, then...
only one out of every six train cars or convoy trucks will carry supplies.
If the supplier for a strat, city, or HQ is above 50%, for every 10 to 15 minutes that go by, 30 minutes is knocked off the clock on down time. You do the math.
AFAIK, these numbers have not been changed in the game. On the large maps, with many zones and fewer field barracks for player resupplies, it was sometimes possible to run strategic warfare against enemy countries with some effort.
With small maps, the only time strategic attacks tend to happen is when the enemy holds bases close to another's strat factories or cities. Barracks are not porked as often now at airfields, since there are more of them (still happens at V-bases and ports).
