Note that Santorum’s approach is NOT a military-first, interventionist approach. It focuses on sanctions that might actually work, combined with the Reagan tactic of funding local democracy movements so they can win their own freedom. Such democracy movements were especially strong in Iran until Barack Obama betrayed them.
It’s true that Santorum favors imposing even more punitive sanctions to continue harming the Iranian population before figuring out how best to launch an unnecessary war against Iran. I’m not sure why this makes his position any better than simple preventive war supporters. Preferring to wreck the Iranian economy before bombing Iran does not reflect admirable restraint on his part. It just reminds us that his preferred policies are completely at odds with his pretensions of being a friend of the Iranian people . Santorum favors covert attacks inside Iran. Iranians are appalled  by the acts of terrorism against Iranian scientists that Santorum praises. His rhetoric about Iranian democracy always seems completely detached from political realities inside Iran.
He does want to offer aid that the Iranian opposition doesn’t want  in the hopes of repeating 1953 (which Santorum believes ushered in an era of freedom ). Good luck finding Iranians interested in taking him up on the offer. Santorum’s eagerness to support anti-regime forces is small consolation for the opposition when the Iranian middle class that has formed its core is being ruined  by the sanctions Santorum favors. As Nader Hasemi wrote  late last year:
Furthermore, after a recent visit to Iran Fareed Zakaria confirmed what Iran experts have known for a long time: Western sanctions have strengthened the clerical regime and weakened the middle class and civil society.
Santorum supports incompatible policies in Iran: aiding the opposition while imposing increasingly severe sanctions on the country that hurt the opposition and employing terrorist attacks against Iranian targets that are widely reviled inside Iran. If Santorum is not a neoconservative on foreign policy, the label doesn’t refer to anything.