I scoped out his countries. He has almost nothing in military assets. Should be an easy conquest if you play your cards right Andrew. First of all you need nuclear defense batteries. 2 per target. They are pretty much 100% effective in stopping nukes. Then you need to deploy some helicopter and interceptor wings to block conventional attacks. Once that is done, you can think about going on the offence. Seeing as how his defences are almost non-existent, you could probably clear him out with stealth bombers and conventional missile batteries. You won't need too many.
If you are in close range to him, or know how to airlift weapons in close range, you can also use offensive AA batteries and land based cruise to save money.