Well, those two are particularly bad examples to use. Being as offensive use of their military is unconstitutional (their constitutions, not ours) after some trouble they ran into with their military adventures a few years ago. They both have been involved in non-combat roles.
If there's a big termite nest eating a stump next to your house, you take some action because it's only a matter of time. I know this military action is hard to stomach for a lot of people. And yes, there are uncertainties and hardships. But it's heading off future catastrophies. You can't afford to ignore things. You've got to lance that boil before it gets infected and you end up with a fatal blood infection. We've had a couple of those in our histories. The types of governments--like Iraq and Iran had and have, and the amount of wealth they have--those are termite mounds. A nuclear weapon would be unthinkable. It's too powerful of a lever to allow them to have. Looking at the tiny things and shaking your fist about specific details is a good way to end up in the 2020 global nuclear war.
What would have happened if Saddam had gotten smart and decided to start doing what the Security Council had told him to do. Gotten in good with everyone while building a nuclear weapon. He could have. We didn't know and that means we could never have been certain. Then, in 2020 he tells us to leave the gulf or he's going to blow up Riyahd and proclaim himself the leader of a new Arab Nation. The Saudi government is hated by Arab hardliners because of how slack it is. None of the maor Holy sites are near the Saudi capitol--Mecca and Medina are 1,000miles away. What is Saddam now has a third of the worlds proven reserves? Why not? WHat are we going to do about it if he has a nuclear weapon that could hit any major European city? We should just hope our 50/50 guess falls on our side?
I'm sure I could think up 20 scenarios about bad things that could happen without stability in the Gulf. China, India, EU, USA all with nuclear weapons and all trying to make a play to keep their oil-based economies from collapsing in the last half century of oil. And the great Arab Nation with nothing else except oil trying to stretch it out to the last because when it's gone, it's back to camel herding, making neat rugs and blown-glass trinkets.
We NEED to be there now as a stabilizing factor. We NEED a massive military base there with armored divisions, depot level facilities, air bases, naval bases--the works. If someone bumps the knob very far you can see just a glint of the results. Housing markets collapsing, food costing 50% more than it did a year ago. Think about a week with no flow. This is what a president has to face. This type of thing you look at from far off and you dig up the stump while you can.