Such as ? When the U.S felt it was under existental threat it definitely responded.
The Madrid/London attacks don't resemble at all the situation between Hamas and Israel - even if Spain wanted to go to war against the terrorists - where would the war happen? Who would they attack? Hamas is right on the border, hell bent on recreating October 7th again and again (their words). And its not just their words Hamas has built an entire army with whatever means they could find, and had fired rockets on Israel repeatedly throughout the years. Madrid and London was one or more sophoisticated terror cell, without knowing what happened there in detail I find it hard to believe it was more than a hundred people involved. Hamas has/had tens of thousands of members, rpgs, explosives, tunnels and tens of thousands of rockets (low quality, but still). Not to mention the fact Israel was immediately attacked by Hezbollah and later on Iran. This comparison to Spain or the UK is simply silly. You simply choose to view Israel as uniquely evil due to your political ideology/own biases and thought processes.
There are plenty of terror groups which the rulers of plenty of countries say are existential threats to those countries, some of them even take hostages, Israel alone responds to those attacks with genocidal rampage.
I think the closest behavior to Israel here is ironically Turkey who engages in brutal military campaign against Kurdish communities on a regular basis. But those reactions don’t come anywhere close in scope as the Gaza genocide.