Section 4A: The Ruined Highway
The Ruined Highway is the official halfway point of the game.
It's also where we make our last route choice of the game... Let's hop to it, then.
As we enter this area, we get a congratulatory message. Incoming transmission!
The 'next operation', by the way, is basically marching up to enemy headquarters and, well, blowing it up.
As for the Ruined Highway itself, there's actually not a lot going on here. It is, however, notable for being the only area in the game where you mostly move diagonally, so adjust your tank's cannon accordingly. It's also a breather for you, as not only is the place only lightly guarded by Louis tanks and infantry- neither of which really put up a fight- but the only pick-ups are Energy icons, so if you took a battering in whatever area you were just in, then you'll be OK. Grab what you need, and press on- you can even ignore the tanks if you want, they won't be bothering you.
Eventually, we'll reach a sign. This is our final path-split!
Head left to go to Section 5A: Long Road Ver. A.
Head right, and after a brief forest encounter with some bombers and tanks, you get another choice:
Go left for Section 5B: Long Road Ver. B, or right for Section 5C: Long Road Ver. C.