You crack me up. "Own defense" ? WTH does that mean if you are joining an alliance??? And yes, we do make up the difference. These countries spend less knowing that we will spend our dollars to protect them. Why do think we have all those military bases in most of those NATO countries? I've served in several of them so I know.

I really do not understand your logic in lambasting the President when he is getting the US out of the business of defense of other countries, which is costing us big. 
Also, if you understand how NATO works better than the POTUS and his plethora of advisors, let's hear it on how you make it work???