Iran hates the Jews. How’s that for justification.
Hate is not justification under the present laws of war.
Iran is extremely cognizant of the laws of war and goes to extremes never to make war. Iran always, that is always, relies on surrogates to make war, and especially to make war in an illegal manner.
The Iranian surrogate Hamas is being exterminated to the last man, woman and child. That extermination is the reason for all of the current Iranian action