I did this mission on my own. Here's the steps I took:
Chose grenadier class, used the default weapon (with 3x zoom) and only ever used it with burst fire.
At all times I scouted ahead with the drone and never stood- crouched to move and prone when under fire.
Went to the right of the army and straight for the AA defence. Switched to grenade launcher and took it out.
Went back the way I came and then down the left to the army. Mopped up any infantry until that objective was complete.
Sticking to the left edge, I slowly went towards the intel and collected it.
Moved along the railroad to the first missile shipment and blew it up (planted a charge in middle of it).
Then stuck to the right edge and slowly worked my way around the map, taking out the other missile shipments on the way. Ammo station just by the second shipment, but wait until after the explosion before you stand there!
After the final shipment is destroyed, the last objective is to take out any remaining enemies. For me, the only ones left were right in the middle. I sent my drone in, went prone and just picked them off. The two gunners in the APCs can be taken out.
For me, the air support blew the APCs up after I took out the gunners. I completed the mission just as the APCs blew up, so I'm not sure if you actually have to destroy them or just the guys on the turrets!
Obviously, the more people you have the easier this will be. It doesn't matter if people die so long as at least 1 person is still alive at the end. I was on my own and it took me just under 20 minutes (of careful creeping!).