If your opponent is securing minor bases while you are just sending Tank after Tank to their Home Base, there will come a time when your opponent will have so much more extra resources that you will have no legs to stand on. So make sure you try to secure at least 2 minor bases. After the game is over, there is a status screen with a couple of stats on there. The number of bases each side secured. The amount of units both teams had.
Most units use up either gas or ammo.
Send these guys into the area and they will resupply the unit when they are out of resources. While the Infantry soldiers are very weak, they are vitalk to the success of a mission. To secure a minor base, you must send 4 Infantry Soldiers inside. They don't use any supplies. The Motorcycle is a fast unit with moderate power.