Why doesn't Paul end all spice production?

Question

(Spoilers for the below are for the first and subsequent books in the Dune series)

In the novel Dune and its first sequel (which is as far as I've read so far), the main objective of Paul-Muad'dib is

to prevent - or at least limit the extent of - a religious jihad, which sweeps across the universe killing countless billions in his name.

In Dune it's revealed that

Paul has a sure-fire way to permanently end all spice production, which could easily be carried out at any time. (See here for how.) In the story he uses this as a threat to the spacing guild, who can use their prescience to see that he'll go through with it if they don't cooperate.

However, my question is why he doesn't just do this anyway.

Some more details:

This would obviously be bad for Paul as a would-be emperor, since we're told his enemies have much bigger stockpiles than he does, and as a spice addict he (and most/all of the Fremen) would die without a personal supply. But on the other hand, as a way to stop the jihad it seems it should be quite effective. It would destroy the Guild and make space travel much more risky. (Without spice there is about a 1 in 10 chance of being destroyed on any interstellar journey.) This would clearly decrease the extent of the jihad, if not make it impossible in the first place. It would also destroy Shai-Hulud and the little makers, returning water to the surface of Arrakis and giving any surviving Fremen the green planet they always wanted. Even if it kills Paul that doesn't really matter, because he considers actions that would result in his death several times and only chooses not to do them because it would make him a martyr.

Of course, an obvious answer is

"Paul's prescience allows him to see the long-term consequences of that action, and they must be bad or he would have done it."

But I'm wondering if it's discussed more specifically than that.

Answer 1

I will mark spoilers for further books (Children of Dune and onwards) but not Dune or Messiah.

In the novel Dune and its first sequel, the main objective of Paul-Muad'dib is to prevent - or at least limit the extent of - a religious jihad, which sweeps across the universe killing countless billions in his name.

This is not actually Paul's main objective, but a personal side objective because he is afraid or unwilling of his main objective - the Golden Path.

Indeed both Paul and Leto II can see the (same) future, and we do not learn what the Golden Path actually is until later.

The humans of the Galaxy must be brutally united, subjugated, bred for specific traits and then scattered, to break their reliance on the current systems of control.

because

otherwise a future threat will be able to find and kill every last human

So it turns out that the Jihad of Muad'dib was required, for the "greater good". Destroying the Spice makes the Path impossible.

Answer 2

There is one thing in my opinion that you have got wrong:

"Paul's prescience allows him to see the long-term consequences of that action, and they must be bad or he would have done it."

The problem with that interpretation is that Paul only saw the Jihad, and no farther than that. It was only Leto that saw beyond it and understood its necessity and significance. In the vision battle towards the end of Children of Dune:

"I cannot lie to you any more than I could lie to myself," Paul said. "I know this. Every man should have such an auditor. I will only ask this one thing: is the Typhoon Struggle necessary?"

"It's that or humans will be extinguished."

Paul heard the truth in Leto's words, spoke in a low voice which acknowledged the greater breadth of his son's vision. "I did not see that among the choices."

So actually you've asked a better question than you are giving yourself credit for. Paul only saw the Jihad and all the death that will happen in his name. He didn't see anything positive coming out of it - only Leto did. So why didn't he destroy the spice?

The answer, as best as I can tell, would be conscience. You can see he is deeply troubled by what goes on in his name. In Dune Messiah, he compares himself to Hitler:

"He didn't kill them himself, Stil. He killed the way I kill, by sending out his legions. There's another emperor I want you to note in passing -- a Hitler. He killed more than six million. Pretty good for those days."

And he knew that he couldn't stop it, no matter what:

"Oh, no. Even if I died now, my name would still lead them. When I think of the Atreides name tied to this religious butchery..."

Paul is deeply disturbed by what is going on under his name, and likely didn't wish to add to it.

Answer 3

You basically answered your own question.

It would destroy the Guild and make space travel much more risky. (Without spice there is about a 1 in 10 chance of being destroyed on any interstellar journey.)

This would doom human civilization, quite possibly unrecoverably. A thousand planets would die a thousand slow deaths; a 10% chance per trip of a journey failing is not actually a rate a complex logistical chain can tolerate. (Even a simpler logistical chain like the Spanish treasure fleet probably couldn't; in over 240 years of annual fleets, only a dozen years saw more than one ship wrecked to weather or attack.) To say nothing of the cost of building a spaceship, which is a lot more than 10x the cost of its usual (non-spice) cargo. Hello again, autarky! Let's hope you're more viable for planets on a century's notice than you were for a country on a year's notice.

Also, Paul can see the Golden Path, and the reason for it, as well as the twins do. Even if the civilization-destroying consequences of killing the Guild are recoverable, if an Outside Context Problem arrives,

humanity is bunched up and will all die.

By preventing the jihad from killing billions, he dooms trillions to a slower death.

Answer 4

Paul's struggle throughout Dune is that the race conciousness of all humanity is gearing up towards war, because of the stagnation of the gene pool which has lasted since the monopoly of the Guild was made. He wants to stop the Jihad but knows that it had to happen to ensure humanity's survival in the long run; he just didn't push it far enough like his son, and that's where he failed. Destroying the spice would stop the jihad, which is great, but humanity will still continue to stagnate.