There is no evidence that links Hamas and Hezbollah actions to the legality of Israel's strikes against Iranian targets. There is no evidence of Iran launching attacks on Israeli targets from its territory. IRGC's presence in Syria was legal. Israeli presence in Syria is illegal.
Israel and USA have been targeting Iranian assets (including bases) in Syria since 2013. Israel striking Iranian targets is a direct act of aggression against Iran. Iranian presence in Syria is/was legal. Israeli and US presence in Syria isn't
Iran is not the only one that has proxies in the region either. Israel is known to support or work with certain groups that align with its strategic interests, though its use of proxies is less overt and less formally structured compared to Iran’s relationships with groups like Hezbollah and Hamas. Which doesn't mean that Israel hasn't used it's proxies to attack Iranian targets (a direct act of aggression).
Israeli itself is a proxy. A proxy of USA. It's actions have nothing to do with "establishing peace" or "stabilizing the region". And everything to do with maintaining US dominance in the region.
