First, Oct 7th was not the start, but it can seem like that to those that regard Palestinians as subhumans who do not deserve liberation and instead are destined to live under the shackles of apartheid, blockade, and occupation.
Secondly, there are various reasons why there is no protesting in this case. Maybe it’s because Israel is the child of US foreign policy? Or perhaps it’s because US veto protection is what has allowed Israel to get away with so much across its history? Or heck, maybe it’s because our taxpayer dollars fund the Israeli gov to the tune of billions of dollars annually (and don’t come with the “it is just weapons” bullshit; money is fungible).
On the other hand, what exactly would be accomplished by protesting against Iranian government repression on US soil or on US campuses?