America has a population that is 35 larger than Israel. If America had lost the same percentage of their population as Israel did on Oct 7th, it would be ~49,420 dead, or the equivalence of 16 "9/11"s. That is why Biden said 10 times worse than 9/11.
Iraq currently has a population of 43.5 million. 187k is 0.42% of it's population. If we do it by percent of population, Gaza has 2 million people, so the retaliation would kill "only" 8,600.