Think on why russia, China, india don't give a shit if mullah regime falls: they know Iran a lot better than burgericans and gafilte fish folks.
The answer is simple: Iran cannot be controlled by an external power because Iranians have strong sense of national identity and get geopolitics. Just as Americans act in their geopolitical interests, regardless of whether red or blue is in power, so too applies for Iran. Toppling Iranian mullahcracy doesn't affect India or China or russia negatively in the long run: Iran will still make NSTC corridor and Iran is a MUCH stronger gateway geographically to central Asia than Pakistan.
They are also far more reliable than Pakistan as an ally and America cozying up to Iran makes Pakistan dispensable for them: they would only need it to act as powercheck vs India and not need it for Afghanistan or Iran.
Russians, chinese, indians all know this, they see it as '5-10 years of instability in Iran if mullah regime is toppled, then we win even more with nationalistic un-embargoed Iran with secular framework, so long term win'
If Americans and Israelis are stupid enough to ignore history- both ancient and modern and think they will make a Pakistan like tattoo who doesn't get geopolitics or its own national interests, let them suffer the fool. Won't be the first time nation building blew up in their face and those who don't learn from history are doomed to repeat it's mistakes.
