Not an easy one really.
Slightly above of a mountain close to the center of the map, with a small hill as well, seems to be only region to set up your base. Build your refinery next to the ore mine to the east, just down of that mountain, and protect this point with gi paradrops and prism towers. It is important to build up your war factory a bit away from your main base, as it is likely to get nuked twice. It is your best bet to start up training harriers as soon as possible !
I advise to keep your battle fortress always mobile (of course with 4 ggis and a seal), wandering and defencing around your CY.
Try to capture as many derricks as possible, and set up the same defence systems around your ore refineries. The higher number of money sources and structures, the better it is! As soon as you train 12 harriers and a spy for sabotage, immediately blow up that nuke. And you will see the mission is getting easier as you slowly maintain and strengthen your economy...