Actually no. The country never makes these interventionist decision. To put it simply, if we see the state in its naked sense only a handful of individuals are making such decisions. Not "countries".
What a superfluous and irrelevant argument - are you arguing just for the sake of arguing?
Two things:
Firstly, if you are correct, why don't we stop referring to nation states as 'nation states' and in fact refer to them as 'the handful of individuals in charge of XYZ-country who are making its decisions'? When we say "Iran did this" or "Pakistan did that" of course we do not refer to every single individual in either of the two countries: we mean that the nation did a certain something. The fact that only a few individuals were responsible for that is irrevelant.
And secondly, you are wrong. Pan-humanism is not one of the defining traits of human beings: we identify with our tribe first and foremost (be that a religious, cultural, linguistic, nationalistic etc definition) - we want what is best for them. As a Pakistani, I want Pakistan to have influence over Afghanistan and India simply in order to assure our own safety.
By that narrative, the Iranian people want themselves to survive and continue existing as a nation: if that means having interventionist policies in neighbouring countries, so be it.
The Israeli support for the recent onslaught on Gaza remained at a consistent 90% and above. A couple of years ago, Turkish armed forces invaded the North of Iraq with majority public support to fight Seperatist Kurds.
You see the best in people - I see reality. If one has to intervene in one's neighbours affairs to guarantee security for one's country, public support for that will always be high.