The population of Israel is 1/9 the population of Iran. The population of the US in 2003 was 10x the population of Iraq. Huge difference in what it takes to actually attempt to occupy a foreign country with a hostile populace.
You realize that Israel and the United States are different countries, yeah?
Every respected strategist said the exact same fucking thing about Iraq before we killed 17 years there. Didn't stop us from trying and failing.