Hamas had to know that if they committed a genocidal massacred enough Israeli men, women, children, and babies, rape women and girls, take hundreds of hostages, and fire 5000 rounds of rockets into Israel on Oct 7, that Israel would have to respond in a very aggressive manner. It is not guesswork!— Then you add Hamas using civilians as human shields, the responsibility all lies on Hamas.
Hamas and Islamic Jihad could have stopped this mess at anytime by laying down their arms, so what ever the outcome is a the ICJ, if Hamas continues to prosecute this war, Israel must continue as well.
If the outcome is “genocide” or the “intention to commit genocide”, the international law applies to both parties, not just Israel, so Hamas and Islamic Jihad would be guilty of the same intention, and even initiated this war with genocidal attack on Israelis of all ages.