Last week, Jeb Bush told an audience in California, "It is strength, and will, and clarity of purpose that make all the difference." This is the Tinker Bell school of foreign policy that has spread over most of the Republican presidential field. Clap if you believe in a stable Middle East where Syria is rid of ISIS, Al Nusra, Syrian President Bashar al-Assad, and any Iranian influence. Clap if you believe Iraq will be safe for religious minorities and free of undue Iranian influence, too.

Candidates who want to lead on foreign policy issues — like Jeb Bush, Marco Rubio, and Lindsey Graham — are offering the American people variations of a very implausible U.S. strategy in the Middle East. And they are underselling the grave costs that even the architects of this policy admit.

In the case of Syria, Bush has argued that "defeating ISIS requires defeating Assad, but we have to make sure that his regime is not replaced by something as bad or worse." Careful readers of this space may remember that this same strategy was enunciated by Rubio, who said, "The reason Obama hasn't put in place a military strategy to defeat ISIS is because he doesn't want to upset Iran," which is Assad's main ally in the region.

At the time I said that Rubio's statement was dumber than a brick in a tumble-dryer, betraying a total misunderstanding of the conflict by failing to grasp that ISIS and Iran are on opposing sides of the conflict. I was wrong; Rubio does, in fact, grasp this basic dynamic. It's just that he — and, it turns out, Bush — believe that the United States can actually defeat Assad and Assad's enemies simultaneously.

In fact, Rubio, Bush, and Graham believe that the only way to defeat one is to defeat the other. Hawkish policy advisers who like the sound of multiple victories at once go back and forth on conspiracy theories as to whether there is some explicit or implicit agreement between Assad's Shiite regime and ISIS's rabidly Sunni forces.

The strategy of defeating ISIS and Assad and Al Nusra all at once originates with Frederick and Kimberly Kagan, who co-authored a white paper on defeating ISIS with Jessica D. Lewis. Even the authors of the paper, normally possessed of supreme confidence in the power of American leadership, seem to admit that it will be a costly and difficult task. And yet, they see no alternative.

Then there's Syria's neighbor, Iraq. Bush last week held out the "success" of the 2007 surge in Iraq as an object lesson for re-engaging in Iraq and Syria. Unfortunately, he doesn't seem to understand the purpose of the surge, which tamped down violence in the hopes of creating a way for sectarian elements to broker a deal. At the time, Jeb's brother helped tip the scales to Iraqi Prime Minister Nouri al-Maliki, a corrupt and sectarian figure himself. And that government could not come to a status of forces agreement, and so the United States left.

The very possibility of asserting U.S. leadership in this region is hampered by our failures in the surge. ISIS has proven itself very effective in punishing and killing Sunni tribal leaders who were known to have collaborated with U.S. forces during the Sunni "Awakening" of 2007. The calculation on the ground in 2015 may be that finding some accommodation with the radicals of ISIS is a safer bet than trusting that the U.S. military won't leave them to be slaughtered in the near future.

How did we get here? During the heady days of 2013, as news reports were flooded with confusing accounts of a use of chemical weapons in Syria, Frederick Kagan's interpretation of the Syrian scene was that four distinct forces were at work: Assad and his military, Hezbollah, Al Qaeda affiliates, and the Free Syrian Army. Kagan concluded, "The only hope of managing Syria's chemical weapons threat lies with the success of the FSA."

The Free Syrian Army has not only disintegrated since that time, but many of its fighters have defected to ISIS or Al Nusra. And the possibility that American air support would create a moral hazard — including a bandwagoning effect in which not-so-secret Islamists joined or even overwhelmed a rebel coalition putatively led by the FSA — never seemed to cross his mind.

At the time, Kagan defined U.S. vital interests this way: "depriving Iran of its forward staging area in the Levant and preventing Al Qaeda from establishing a safe haven there." It is because U.S. interests are defined so broadly that so many Republican presidential candidates are advocating what sounds like an insane strategy: dropping 10,000 to 20,000 American troops across northern Iraq and Syria, and marshaling, somehow, a coalition of regional "moderate" Sunni forces that will defeat at least three battle-hardened sides in a brutal, zero-sum, and long-lasting civil war.

Beyond that, the Kagan-GOP hopeful strategy is to somehow re-construct a "moderate" force like the Free Syrian Army as a "New Syrian Force," in order to have someone to hand power over to when this conflict winds down. For now, the idea of a final victor in the battle for Syria is labeled "TBD." In Iraq, the same.

Notably, the Kagan plan leaves open the possibility that Syrian moderates may be insufficient to the incredible tasks U.S. interests assign them. And further, Kagan, though very much a supporter of U.S. leadership, admits that U.S. forces would be entering an extremely confusing battlefield situation where ISIS has captured enough war materiel to disguise themselves as other forces, a trick they've used effectively against the Iraqi security forces.

Because the overriding regional concern of Republican hawks is the de-legitimization of the Iranian regime, policy experts and candidates are already ruling out the most obvious ways of defeating ISIS, such as collaborating with and strengthening Assad's forces and the Iraqi army in their respective territories. Instead, the idea is to defeat everyone at once, at low cost, without ugly alliances, and to the benefit of unnamed good guys.

And you thought the first regime change in Iraq was tough!

As an electoral strategy, it is absolutely nuts that Republicans would preemptively tell the American people, "Elect me and I'll put American troops back on the ground in Iraq." And then add, "And Syria, too, and with allies TBD, and final victors TBD." This seems like a 2016 death wish. Not just for Republican electoral ambitions, but for American troops, American prestige, and American power.