TAMPA, Florida (Reuters) - A military strike on Iran could have the unintended consequence of stirring nationalist sentiment to the benefit of Tehrans hard-line government, US General David Petraeus told Reuters. Irans June election gave President Mahmoud Ahmadinejad a second term but sparked the worst internal crisis in the Islamic Republics history, putting internal pressure on a government already facing the threat of more sanctions over its nuclear program. Its possible (a strike) could be used to play to nationalist tendencies, Petraeus, head of the US Central Command region, which includes Iran, said in an interview this week. There is certainly a history, in other countries, of fairly autocratic regimes almost creating incidents that inflame nationalist sentiment. So that could be among the many different, second, third, or even fourth order effects (of a strike). Petraeus, commenting on advances of Irans nuclear program, said: On the one hand, there is no question that there has been a continuation of various aspects of the nuclear program but Im not sure it has always proceeded as rapidly as has been projected at various times. Petraeus cautioned that the big winner of the election had been Irans security apparatus, expanding the influence the Revolutionary Guards Corps, including its elite Qods force. Its gone from I think a theocracy that had democratic elements in a narrow spectrum ... to a government that is the result of a hijacked election and a regime that is kept in power by security services to a vastly greater extent than has ever been the case before, he said. Asked how this changed prospects diplomatically, Petraeus said: I dont think it simplifies the situation for those who are trying to pursue diplomacy if the role of the Foreign Ministry is diminished further and the role of the Qods force has been augmented. To counter the Iranian threat and reassure anxious Gulf allies, the United States has expanded land- and sea-based missile defense systems in and around the Gulf. Petraeus stressed it had been a gradual build-up an approach shared by both the Obama and Bush administrations and not something sparked by events in Iran in recent months. This has been built up over years of inflammatory Iranian rhetoric, alarming Iranian activities and Iranian provision of arms, money, training, explosives and direction in some cases to a variety of different extremist elements, Petraeus said.