How so? The results speak for themselves. Syria, Yemen, Libya, to name a few. I am open to changing my mind if you can provide empirical evidence.
How is a foreign policy defined by the Quran? What are its exact tenets? How has Iran implemented them?
What other options did Iran have? Iraq, Syria, and Libya all stood their ground. Every country does when it comes down to existential threats. Iranian policies of the previous 4 decades led them there, which they also seem to have realized. I've discussed this at length here before.
I was pointing towards Iran's bonhomie with India despite its continued atrocities in Kashmir to contest
the claim of "Shias have always come to the aid of their fellow Muslims". There's plenty of other examples throughout history.
People in groups overwhelmingly tend to their own group's interests. Any spillover is usually owing to chance alignment of interests. Always has been, always will be. The formation of nation-states has decoupled people's interests from every other grouping; political, religious, ethnic, and sectarian. They are now exclusively dictated through one's country. Not so much the emotions of Pakistanis, which are still governed by these archaic allegiances. So, with confused senses of belonging we still divide ourselves in different groups within the same nation.