Reasons for the invasion matter of course, but they matter for different people. The American people deserve to know why their treasury is being expended on a war half across the world instead of being used to improve life at home. Or exactly what improvements they reap in terms of security by fighting this war, if their administration is going to tell them that Iran is two weeks from getting the bomb for the last decade anyway.
But these reasons are irrelevant for Iran. Trump could be attacking Iran because he legitimately feels threatened; or for its oil; or to distract the public, or maybe simply because he wants to build a Trump Tower&Casino in Persepolis. The point is that, whatever the insane reasons the United States have for their attack, Iran CANNOT prevent them from acting upon them. Nor can it change the minds of those in charge of writing American foreign policy; no more than the Zulus could change the reasons for why the British Empire attacked them, for example.
What Iran CAN do is set clear consequences for attacks on its sovereignty. "You strike our Consulate. Fine." Two days later Hzb retaliates on a diplomatic mission of the Epstein Coalition. "You kill our officials. Okay" A week later an American military contractor happens to "disappear". And so on. This is tit-for-tat retaliation.
Reasons for war are for the American people to debate on. And I agree with the idea that with such baseless reasons, it really does show the corruption of the leadership that started this war, as well as of those who do nothing to prevent it. But for Iran, it isn't about determining whether the reasons of their attacker are good or bad. It is about making the likelihood of an attack go from possible to impossible, without significant casualties. And Iran has blundered massively on the latter.
Apologies, your Majesty. A Great White is indeed a formidable creature. Trump is nothing like that, although he is trying too hard to be...