Go to the weapons development screen and keep attempting to get new technology.
Keep trying until you get heavy bomber, jet power, and long range aircraft. 
Then, buy a few bombers. You will obtain powerful bombers with eight movement
points. Also, if you have "paratroopers" enabled, they can carry two infantry.
The eight movement point bonus allows these planes to fly almost everywhere on 
the map. Two at once infantry transport added with its range makes this plane 
a perfect way to start an assault from anywhere, to anywhere. This is a time 
consuming (and possibly IPC consuming) strategy, but worth the effort. To make
this less IPC consuming, start a game however desired. As soon as the game 
begins, save it. Play a few rounds. If you think you are in good shape and 
are getting the correct technologies, continue. If not, try again.