I was initially siding with Israel as they were hit first, but their response has made me rethink things.
To generalize this out to other wars and conflicts, even regular old arguments, there are almost always pre-existing conditions and tensions leading up to the first major attack. Even things like WWI, where the catalyst was the assassination of Archduke Franz Ferdinand. But there is quite obviously more to the atmosphere, national ambitions, etc. etc. that make it so that the separatists wanted to assassinate him, and make it so that Austria-Hungary wanted to invade Serbia and used this as an excuse. A war would have happened anyway, no matter who attacked first.
Ah, that sucks to hear about.