Explanation and hints for Mission 2.
I know this mission is a bit hard to understand and complete. My bad. However.
First tips will only give some general information. That will help if you miss or misunderstand something.
Latest will give you advice on how to beat mission.
1. Mission is very hard to beat, if you commit direct head on attack on the enemy.
2. Main idea is to accomplish secondary tasks. Then investigate what will happen and how enemy reacts on your different actions.
It might require some save/load.
3. There are 3 options with fuel truck:
a. Do not stop it.
b. Stop it and then put driver back.
c. Stop it and keep it.
Last option is hardest one and will cut a lot of opportunities. But it is also an option.
If you were unable to accomplish mission, choosing option c. Try other ones before reading next tips.
I will describe next tips considering you choose a or b.
4. After enemy got fuel it will start sending some vehicles as a recon teams. They will retreat if attacked. If one of recon teams reaches exit, reinforcement will arrive from exit direction.
5. When you alert enemy 3 times, it will send some troops to nearby villages.
6. It is possible for vehicles to reach north-east corner of the map. Infantry can attack a gas station from north over the hill.
7. Do not forget that infantry can rearm inside vehicles. Trucks have a lot of ammo. And mouse(GRU) can plant explosives.
8. Vehicles leaving gas station as recon teams is an opportunity to lower the number of enemies at gas station.
9. If you allow reinforcement to come, there will be ammo truck.
10. When enemy sends troops to nearby villages, it also means there are less on gas station.
Direct guide, how to accomplish.

1. Deal with secondary tasks. You can capture 2 more vehicles on repair base if kill drivers fast. Not critical.
2. Refuel vehicles, rearm troops in trucks.
3. Stop fuel truck and let it go.
4. Ambush first recon team. Send some troops to ambush/scare off second in east. Leave mouse in the east, so it could ambush again if needed.
5. Western recon will try to go north-west. Ambush them. Now act fast.
6. Enemy will send groups to nearby villages. Reach old tower in the north-east(where enemies are heading). And eliminate enemy(ideally before they reach tower)
7. Send your troops(inside vehicles) to the area north of gas station.
8. Attack gas station from north(over the hill) with infantry. Use smoke to cut some directions of enemy fire. Snipers could try killing mortar team.
You can roll back to heal rearm and attack again.
9. Attack heli when it tries to land (use W attack with all weapons).
10. Get close to gas station house. This will trigger hostages to kill anti-tank team. Be ready to cover hostages with smoke and evac north.
11. Now you can start moving your tank by the road (from north-west of gas station). Deal with most dangerous vehicles 1 by 1.
12. At some point there will be a task to capture a radio tower, an easy one. Just react quickly. Your gas station attack can wait.
13. Put smoke around the "cargo" vehicle and steal it. No need to eliminate all enemies. No need to drive south past gas station.