This is the chapter outside the bomb shelter. Move you units right and capture the factory and airfield first. First concentrate on building tanks and blockade the gaps in the mountain range in the middle of the map. As soon as you have enough money build rockets and Mech guns and position them behind the mountains to fire at oncoming enemy troops. Do not worry too much about the enemy air units. Position your air units towards the centre of the field just outside the enemy's air units range.
Gradually build up your forces and push east. A tactic I always like to use is to have my aircraft attack and destroy the units just made on the enemy's factory's and airfields and then use a second wave of aircraft to fly over the factory's preventing them building more units next time. For this to work effectively the enemy has to have no Anti-Air or Interceptors.
Do not forget to protect your Missiles, Mech guns and Rockets from direct attacks from the enemy!
Good luck