When I think of ranking dumb decisions, I focus not so much on the total damage (Vietnam and Iraq war will contend on body counts, financial costs, ramifications for alliances, etc) but on comparing the likely upside/downside ahead of time. That is, was this a difficult decision or was it a no-brainer that the opposite should have been done. Via that standard, today's dumbness competes only with disbanding the Iraq army as decisions that had very little going for them and very much going against. Vietnam? Each incremental decision was a tough one--help France or abandon an ally? How best to confront communism? Once in, do you go with the corrupt, incompetent government you have or one that might be better? And on and on.
To be fair to the Bush Administration, Iraq was a tough policy problem as the sanctions were harder to sustain and they were punishing the people without hitting the regime very hard, that Hussein was trying to have it both ways--that he did and didn't have weapons of mass destruction programs, and so on. Still a dumb decision given how likely it was to empower Iran, but one could see some upside in eliminating Hussein (which was the goal of the effort, not much more than that really). But disbanding the Iraqi army? No upside as we know that firing lots of young men with guns is a baaaaaaaaaaaaaad idea.
So, let's consider the pro's and con's of getting out of the Iran deal:
- Makes Trump feel good about ditching an Obama legacy
- Makes Netanyahu happy.
- Removes key impediment for Iran to develop nuclear weapons.
- Antagonizes allies even before Trump starts punishing European firms for trading with Iran.
- Should make it harder to make a deal with North Korea since it shows that the US won't keep its end of a bargain.
- Increases the probability of conflict with Iran.
- Plays into the hands of China and Russia.
Why is this happening? One could argue that perfection is the enemy of the good enough, as the Iran deal was not perfect BUT this is giving the anti-deal folks too much credit. What if Iran was willing to have intrusive inspections forever and was willing to stop developing missiles forever? Opponents would say it does not stop their support of terrorism. The only way to get a country with its own domestic politics and its own agency to do everything you want is to ... invade it and replace its regime with your own occupation forces. And we kind of tried that and it hasn't worked out so well.
It comes down to this: the US can't impose its will and get everything it wants. It simply can't. This is the neo-con dream, I guess. Trump? He is just a dreamer, I suppose. No, this is happening because Trump has a dumb and disproven view of international relations--that one can just wish things and they will happen. Recent news suggests that Trump and his folks believe their own press (that is, their own press office and maybe Fox)--that being tough on North Korea has led to this momentous deal that they will have at the summit, and that this is the answer to all of US problems--bluster and threats and aggression.
Not only is this reminiscent of the stance of the Kaiser before World War I (worked out great for him) but runs against everything we know about international relations. It almost seems as if it is the mission of the Trump folks to hasten American decline--by alienating allies, by undermining American credibility, by spending lots more money on the forever wars of the future, by strengthening adversaries, and on and on.
This might not be the dumbest foreign policy in US history if there was even a half-assed plan to replace the deal. I am pretty sure the plan really is two parts: Trump saying fuck Obama; and Bolton and the other anti-deal folks saying: woot, regime change! Does that count as more or less than half-assed? So, yeah, I may have to stop saying that disbanding the Iraqi military is the dumbest decision in recent US foreign policy history.