They'll Defeat Themselves

One of the things that was astounding about the economy of the ex-Soviet Union was that, on average, it managed to consistently destroy value:

The Soviet economy was value-subtracting rather than value-adding throughout its life span. Explained simply, the world market value of almost all Soviet-made products was below the world market value of the natural resources and direct labor used to produce those products. The seemingly inexhaustible supply of easily-extracted natural resources made this possible.

The Soviet economy was not sustainable. It was doomed to failure from the beginning. Perhaps Reagan hastened the collapse, but it would've eventually failed no matter what. There was only so much value they could afford to subtract before they could no longer continue. Reagan was in the right place at the right time.

The larger the Soviet empire, the faster value was subtracted. Most of those east-bloc satellite countries were subtracting value at a good clip, as was Cuba and other client states. This depleted the Soviet's easily-extracted natural resources faster than if Russia had just operated on its own. In addition, the cost of maintaining a military presence in all the client states to enforce communism exacted a further toll on the Soviet's treasury.

From this, it follows that the collapse of the Soviet Union would've occurred even sooner if they had taken over the entire world except the United States. There would've been some other advantages as well. All of the other nuclear powers would've been united under Soviet control, so there would've been fewer problems with proliferation. Terrorists would've been focused solely on the much larger (population wise) Soviet empire and wouldn't've worried about the United States at all. When the collapse inevitably occurred, instead of being the sole super power, the United States would've been so far ahead of the rest of the world that we would've been the sole super-duper-hyper power in comparison. For sure, it would've been unfortunate for another few billion people to live under Soviet tyranny, but let's ignore the moral argument for now.

If we had let the Soviets take over the middle east, what about all the oil? Well, if the Soviets had taken over the whole world, hardly anybody would be using much oil other than the United States so it would be dirt cheap and they would've been dying to sell it to us (so they could do more value subtracting). Even if I'm wrong about that, the United States had (and has) adequate resources including oil and the markets would've adjusted the prices to allocate those resources efficiently and innovations would've come into being that would've mitigated any serious shortages. It would be a different world, but we'd still be way, way ahead.

While I think the domino theory was correct, I think we should've considered just letting it happen. So sorry Vietnam, Cambodia, Laos, Thailand, Myanmar, Bangladesh, India, Pakistan, etc. But it would only be for a few decades. Don't get me wrong - once we decided to go into Vietnam, I think we should've stayed as long as needed. I just think that if we'd just stayed home and let the dominoes fall, it might've been a feature, not a bug.

Now let's consider a Grand Islamic Caliphate which united Muslims from Morocco to Pakistan and perhaps Indonesia. A Taliban-like rule of shari'a law oppressing over one-billion people. This would also be a wonderfully non-sustainable regime and not just because of economic value subtraction, either. The Taliban took Afghanistan all the way back to the stone age and kept it there and I think it quite likely that a Grand Islamic Caliphate would do the same for the entire Muslim population.

A people that oppressed, backward, and poor would pose no significant danger whatsoever to the west.

I know what you're thinking: they'd figure out some way of producing weapons of mass destruction and use them on us!

Oh yeah? How? Somehow they'll add sections on nuclear physics and biology to the Qur'an and study it in the Islamic Madrassas? I don't think so.

Note that the only Muslim country that has successfully tested a nuke is Pakistan and they developed that capability when they were a democracy. The only other country that's close is Iran and they're an almost democracy and they haven't succeeded yet anyway. If the whole region was under a Grand Islamic Caliphate, there would be no way for them to even maintain the current nuclear capability of Pakistan, much less expand it. Furthermore, since they'd be a "grand and great" nation, they'd be deterrable. The people at the top (Osama bin Laden I presume) would want to wait until they could do some real damage to the west before risking total annihilation, and that day would never come since they would being sliding backwards towards the stone age.

In my opinion, since we're in Iraq, we ought to finish the job, however long it takes. Especially since al Qaeda has been beating themselves:

Al Qaeda has been badly battered. It's lost top leaders and thousands of cadres. Even more painful for the Islamists, they've lost ground among the people of Iraq, including former allies. Iraqis got a good taste of al Qaeda. Now they're spitting it out.

Also:

Some of these men will admit they were insurgents who switched sides because they realized that they are more likely to get what they want with a stable government. Al Qaeda promised them everything under the baking sun, yet al Qaeda killed people who smoked—and Iraqis like to smoke. They killed people who had satellite dishes or televisions, but al Qaeda would be drinking and with prostitutes. Iraqis have told me some interesting anecdotes about the religious technicalities of prostitution. They are not supposed to have sex out of wedlock, so they marry the prostitute (and the house of ill-repute has the proper religious authority present to make the marriage), and then they divorce the prostitute after completing their business. Another rumor in the area is that al Qaeda tried to force shepherds to make their female sheep wear underwear...

But I do wonder if just letting Osama achieve his vision of his Grand Islamic Caliphate wouldn't've been the easier path.

Our enemies always ultimately defeat themselves with their non-sustainable ideologies. All we have to do is wait and go about our lives.