Persia's last shah was a coward and a weakling. Your assertions to the contrary cannot change reality, better get used to it. And Iran was little more than a british protectorate from the beginning of the 20th century to the 1950s, when british control over the Middle East had to be relinquished to the US. It wasn't turned into a colony outright because, like Afghanistan, it served as a convenient buffer between the Russian and British Empires. It remained an american "protectorate" until the 1979, and was lucky enough to claim its full sovereignty at a time when the Cold War balance prevented any overt application of military power to subdue it again.
Iran hasn't been a great power at least since the Mongols showed up. And any attempt to make it into one now will only bring destruction: it doesn't have the resources or the demographics to be anything more that a regional power, and it would be better of just defending its own sovereignty and leaving ruinous imperial wars to others. Look at what such ambitions brought to its neighbor.
You are a dangerous nationalist, of the kind blinded by wishful thinking. Dangerous to your own nation.