When Iran is free there will be no need for the USA to police the West Asia anymore. This is because Israel and Iran as the closest allies of the USA and eachother will fill that policing role in that area of the world instead in the absence of the USA therefore this means the USA will be able to focus on policing East Asia against the threat of China.
When Iran is liberated and is managed by it's future legitimate Democratic Government it will take 5-10 years for Iran to reach to very high military power again like the 1970s under the Shāh and like back then Iran will be capable of contributing militarily and security-wise to become a reliable political partner to Israel and not be just a lazy ally to Israel
It will take at least 5 years because the future Government of Iran must re-orient and re-structure the military back to it's original healthy and sensible Nationalist purpose by elimination of all problematic Islamic elements that corrupted it in the past 47 years. The future Government of Iran must also put in new military leadership after arresting the current Muslim criminals who are in control of the military and lastly the future Government of Iran must invest in military technology, equipment and innovation like the 1960s and 1970s again to make Iran powerful again like under the Pahlavi Dynasty for Israel to feel comfortable enough that Iran can keep up with Israel as they team-up and collaborate together again to maintain security in West Asia in behalf of the USA