The only thing incoherent is your failure to acknowledge the undeniable. That the US and Israel has targeted civilian infrastructure first, a school, and an Iranian desalinization plant, and now Iran has stated terms that if the US or Israel decides to escalate further, this is what will happen.
If Iran has to do this to deter the aggressor nation to make the war politically unfeasible in the aggressor countries and for those that support them, then it's completely understandable on their end. What else would you expect the underdog nation on the defensive to do? Roll over and die?
To illustrate, the responsibility for morality and restraint is for those who have the upper hand. As an adult, you can choose to treat a small child with decency or you can abuse it, but it is very difficult for the child to impose things on you unless the adult left open a vulnerability. You for one believe the US is much stronger, this puts the responsibility of decency on their end, which IMHO the US hasn't been doing as shown by the fact that due to US/Israel middling in the Middle East. Christians have lost protections they once had, and their population is a fragment of what it once was.