I have to take exception to your statement that he wants to "disengage the world". His views are often mislabeled as "isolationist". The correct term is "non-interventionist". He wants to engage the world by having diplomatic relations with, and trading with, as many countries as possible.
Congressman Paul's viewpoint is the result of a lot of study in this area, and I can't do it justice in a Free Republic post, so I recommend listening to his recent foreign policy speech at Johns Hopkins University. It's quite compelling, and he lays his case out in a way that is not allowed for in the debates or on talk shows.
Some times you need to smack folks up side the head