Some of the existing outlooks view the characteristics of Iran's power structure and politics in such a way that make any security-political, economic and cultural coalition and cooperation difficult in the region. But the author holds that political, security and geopolitical changes in the Middle East region after the September 11th events have reinforced the place of regionalism in Iran's foreign policy. Iran's strategic value and role in boosting regional factors are related to such factors as strong nation-state, geopolitical identity and dynamic Shii ideology. In this relationthe author defines two concepts of traditional regionalism and new regionalism in Iran's foreign policy orientations, each of them seeking to secure Iran's national interests and security with a different outlook. The author concludes that the Islamic Republic of Iran has to resolve political-security dilemmas with trans-regional powers including the United States by redefining elements of its national power at the regional level