I wasn't implying that all those changes happened bloodlessly - horrible things happened.

But what Ahminedjad's ill-judged words have been taken as implying is a threat of nuclear holocaust, and in that context "the same people and their descendants are living there today" is a relevant reminder that calling for regime change generally does not imply that.

There are of course people threatening nuclear holocaust. In this thread for example. That doesn't matter - so long as the people with the power to carry out those kind of threats aren't in a position to carry them out.

That of cause implies trying to stop people having nuclear weapons.. To adapt Tony Blair's formula, it is important to fight nuclear proliferation, and the causes of nuclear proliferation. In the case of Iran that should mean some kind of guarantee that there will be no attacks on a nuclear-unarmed Iran - surrounded as it is by hostile or potentially regimes which do have nuclear arms. (Israel, Pakistan, Russia, US occupied Iraq.)