We have been standing down and reaping the "benefits" for 40 years.
Is it your desire that we continue to ignore the issue so our grand kids can deal with it?
I do understand your logic and desire but when is enough enough?
When we decided to kill Soleimani. Following that, Trump publicly told the entire nation, and the world, that he wasn't trying to start a war, but to prevent one. If he does as you suggest, he'd be rightly tagged as a huge liar who misled the entire country.
Iran is in trouble. They've had mass protests because of a tanking economy, and we just took out one of their most important figures. Let's see where this goes before escalating and potential losing any advantage we may have just gained.
We can do a lot of damage to Iraq with missiles, but not enough to remove the mullahs from power. If you really wanted to do that, you'd have to invade by land, and that's not happening. Even manned aircraft would result in a lot of guys getting shot down and muddying up the situation. And if we just decide to take out their port facilities/oil production, we're going to throw much of the rest of the world into a recession because of the disruption to oil supplies. At that point, with little left to lose, Iran may just decide to fire off 1000 or so ballistic missiles at other cities in the region. Non-nuclear, but a lot of people would still get killed, and everyone would blame it on us. Might even swing enough Senators to convict Trump.