Thomas Barnett has already said that war with Iran is inevitable for the U.S., but he now argues that deposing Assad would make it less likely:

The debate among U.S. foreign policy analysts over the wisdom of an Israeli attack on Iran’s nuclear facilities — and whether or not America should allow itself to be drawn into an ensuing conflict with Iran should Israel strike — has largely taken place parallel to the debate over whether to pursue an R2P, or responsibility to protect, intervention in Syria. It bears noting, however, that forcing Syrian President Bashar al-Assad’s departure may be the best near-term policy for the U.S. to avoid being sucked into an Israeli-Iranian war.

This is a hard case to make. It gets harder to make when Barnett wrote just a few weeks ago that Assad’s eventual fall would reduce Iran’s ability to retaliate against Israel, and that meant that an Iranian war that pulled in the U.S. would follow the end of the Assad regime:

So get ready for war with Iran. Because once Assad is gone, that is what comes next.

Three weeks later, Assad’s downfall is now the best insurance against an Israeli strike that pulls the U.S. into a new conflict:

Once Assad falls, whatever the outcome, we have isolated Iran further, lessening its bravado and increasing its desperation. If you want to stave off an Israeli attack, this is the route to go. Moreover, removing Assad will create an exit scenario for Syria short of true chaos — meaning civil war, with all the locals driving the process to deeply conflicting ends — which could easily become the trigger for direct Israeli-Iranian kinetics, first inside Syria and then beyond. Syria is simply too important an outcome for both of them, as well as for Turkey and the GCC countries, for any of them to eschew the dangers associated with interventions of some level.

With all that ambition at stake, it’s better for the West, along with Turkey, to impose an overarching and overwhelming dynamic upon the situation to steer it toward the preferred outcome of Assad’s fall. Again, Moscow and Bejing will shriek in response, but we’ll get what we want in the end — namely, Iran’s top lieutenant dethroned and the Arab Spring’s momentum extended to Iran’s doorstep. That outcome will do more to stay Israel’s hand on Iran’s nuclear program than anything else we might manage to come up with. Indeed, compared to the Western embargo of Iranian oil, which will eventually push Tehran into forcing the issue of war with Israel, Assad’s fall is far more likely to force some Iranian compromise with the West’s resolute opposition to its nuclear ambitions.

Besides the small problem that Barnett’s two columns present flatly contradictory analyses of the effects of Assad’s removal from power, what we find in the new argument is a demand for some form of intervention directed at regime change in Syria as an implausible three-for-one success. According to Barnett’s latest argument, deposing Assad punishes him for the brutal crackdown, deprives Iran of its regional ally, and supposedly makes Israel less inclined to attack Iran. How is the first to be achieved? By means of an even more implausible Turkish invasion:

And when that proves not to be enough, then we ought to encourage Turkey’s invocation of its NATO membership to request alliance military operations designed to enable a Syrian rebel victory. The pattern here should mirror that of the Libyan operation, but with Turkish military forces playing the lead role wherever possible in securing sanctuary for civilians and rebel forces.

First of all, NATO isn’t going to agree to this. Most NATO governments never wanted anything to do with the Libyan war, and even fewer NATO governments want to be involved in Syria. Other NATO governments would remind Turkey that it provided as little support as it possibly could to the Libyan war, and they won’t want to be dragged along for yet another conflict that could become much more difficult, prolonged, and costly. Elsewhere at WPR, Nader Habibi explains why Turkey is not going to accept the role Barnett is offering them:

The reason is simple enough: The Assad regime’s three key international backers, Russia, China and Iran, are among Turkey’s largest trade and investment partners. Any active Turkish involvement in a military intervention targeting Assad would pose a substantial risk to Turkey’s relations with these three countries, at potentially great cost for the Turkish economy.

Supposing that there was some way to engineer Assad’s removal from power, it still doesn’t tell us how a U.S.-backed proxy war against Iran’s regional ally makes conflict between the U.S. and Iran less likely. Indeed, by definition, it will mean that the U.S. and Iran are actively supporting rival sides in an armed conflict that could escalate to include some of the rival patron states. If Iran loses its regional ally, that isn’t going to make their government value the nuclear program less, and it is going to encourage Israeli hawks to believe that they can strike Iran with relative impunity. They might still be wrong about that, but Assad’s fall definitely could reduce the threat of Iranian-backed retaliation and make regional war more likely. Barnett’s new column reads like a very forced attempt to reconcile support for an R2P-based Syrian intervention with the desire to avoid war with Iran. Those two can’t be reconciled, and support for the former could help pave the way to the latter.