I say again: regime change in a country is a matter for that country. A possible exception is if a legitimate ruler seeks support from allies - but at the moment that is a circular argument for Iran.

It is however becoming clear that the present Iranian regime is using illegitimate tactics to prevent peaceful and constitutional regime change. That legitimates otherwise illegitimate tactics by those being targeted - so long, of course as those tactics do not involve collateral damage to non-aligned people.

Simples.