Im talking about pill box's,trenches,barbed wire,Walls,misile silo,guard towers things that dont move but add to your strength for example.
Pill box +1 to infentry defence
Trench -1 to attacking tank attack
Mistle silo mistles get hit only after tanks and infentry are remove by attacking ground units or air units cant hit them
Barbed wire defending infentry get 1 free attack
things like that are needed there additions that make it posible to have a smaller country and hold out against overwelming odds.
also i put a New post together to explain it again to help better explain things.