Rand Paul gave a big foreign policy speech to the Heritage Foundation today, in which he presented a greatly tidied-up version of the elder Paul's anti-interventionism as the true expression of Reaganite foreign policy. It was an interesting speech, filled with historical references and sourced quotes. Rand is far more persuasive and polished when presenting such ideas than Ron ever was.
Among other improvements, Rand doesn't wave away the concerns of more hawkish foreign policy proponents (although he couldn't resist slipping in a dig or two at the "neocons.") Thus, unlike his father, he's clear that Iran is a big problem that we have to deal with, perhaps violently. But he's a strong proponent of trying everything else first, aligning himself with Israeli leaders who have deep reservations about taking out Iran's nuclear program with military force.