Following official announcement of oil embargo on Iran by the EU, official positions of Islamic Republic were introduced by political and military authorities based on “blocking Hormuz Strait under certain circumstances”; an issue of great concern in western officials. They warned about their military capabilities in the field of reopening Strait and maintaining security of energy transit lines in the Strait of Hormuz. They questioned the West military methods against Iranian military officials reopening the Strait of Hormuz.This study seeks to answer this question that “what are Iranian military capabilities to block Hormuz Strait?”, “If the Strait is blocked, when western military forces can reopen it?” “Iranian military capabilities which can be called ‘five pillars of military strategy’ based on cruise and ballistic anti-ship missiles, small speedboats, drones, small submarines, nautical mines and standoff missiles supported by air defense and electronic warfare (Jangal), allows Islamic Republic to block Hormuz strait in long term. However, previous to any military conflict with trans-regional forces, the main Iranian weapon is nautical mines to block Hormuz Strait”.