Perhaps in a world where Dr. Paul thinks is "old world" as it was BEFORE the airplane, rocket, and missiles, his "foreign policy" was fine. Today, we can reach any point in the world in under 12 hours as can our enemies. To believe we can "protect our borders" with that isolationist policy is not only foolhardy, but sheer stupidity.
We can't expect OTHERS to play by the same rules of isolationism. THEY WON'T and DON'T. Having strength deters those unyielding "bad apples". Read Jefferson's response at the Barbary Coast Wars and then you can shut up.