On the south end of my county there's a four lane bridge across a lake. On the West end of my county there's a four lane bridge across the lake. If the South bridge is out you have to go 30 miles to the east to cross the east bridge or thirty miles to the west to cross the river and circle around the lake. Coming from the west is a two lane that runs alongside the lake and a mountain ridge on the other side of the road. From the north you have to cross the mountain ridge on a four lane through the gap.Just assuming you can go anywhere isn’t a valid assumption. There will be roadblocks with a SOP of “shoot on sight “
Pretty easy to defend all approaches to the county.