“The World Has Changed,” trumpeted the front-page headline of the Iranian reformist daily Etemaad on July 15, the day after Iran signed a nuclear deal with the six world powers. But as U.S. President Barack Obama attempts to build on this agreement, he will find that changing the destructive dynamics of the Middle East is far more difficult than any negotiation in Vienna.

For years, U.S. leaders have staked their hopes for calming decades of sectarian war, insurgency, and tension in the Middle East on rehabilitating Iran, a bête noire in the eyes of Washington and its allies. But if there’s any hope of changing these dynamics, the United States is going to have to dive quickly and deeply into the region’s feuds. Wars have spiraled out of control in four Arab countries, and Iran is only partly to blame. A more cooperative Tehran — which may or may not materialize after the nuclear agreement sinks in — could open the door to calming the bloodshed in Syria, where Iran is a lead player. But the roots of the wars in Iraq and Yemen go deeper than Tehran’s machinations, and Iran has almost no role in the Libyan conflict.

After the deal, like before, U.S. interests will be challenged by clever and aggressive foes, but also by ruthless allies. If the United States wants to alter the dynamic, it will have to give up its linear approach and play what Joseph Nye describes as “three-dimensional chess.” Until now, Washington has insisted on taking on one crisis at a time, meaning that a pileup of disasters has festered while the White House looked only at the Iran nuclear deal.

That mindset won’t work. It will take far more than a change in Iran to end the Syrian civil war. Same for Yemen.

So, what will work?

First, the United States will have to engage Iran and other bad actors in each of the region’s hot spots. Obama has already expressed the intention of doing so: At his press conference on July 15, he spoke of “[jump-starting] a process to resolve the civil war in Syria” and that “it’s important for [Iran] to be part of that conversation.”

Second, at the same time Washington tries to engage diplomatically with Tehran, it will also need to raise the costs for Iran of continuing to do business in the same bloody way it has across the region. With billions of dollars flowing back into the country after the lifting of sanctions, there’s a risk that the Islamic Revolutionary Guard Corps will intensify its expansionist approach and investment in proxy wars. A direct war with Iran isn’t a wise option, but ignoring its machinations has left it free reign to expand its dominion in Iraq, Syria, Lebanon, and Yemen. The only remaining option is to engage in messy proxy warfare as well, giving sustained military and political backing to anti-Iranian proxies, which will make it expensive for Iran to meddle around the Arab world. This will give the United States a new card in the negotiations to come: It can offer to restrain its proxy militias if Iran does the same.

Third, the United States will face the challenging task of getting its recalcitrant allies onto the same page. In the Syria conflict, that will mean butting heads with Turkey, Qatar, and Saudi Arabia, all of which have poured money into rival rebel factions, allowed a free-for-all in the border zones, and paved the way for the entrenchment of hard-line Islamists within the uprising. Washington will need to convince its partners to pick a single rebel coalition to back and then endow it with real and sustained support. That’s the only way to tilt the balance inside Syria and increase the likelihood of a political solution that empowers nationalist rebels at the expense of President Bashar al-Assad’s regime and the radical Islamists.

After years of myopic focus on Iran’s nuclear program, the United States will have to take an unsentimental and cleareyed inventory of its dysfunctional allies. It can only expect so much from Saudi Arabia, Israel, Egypt, and Turkey — but with these sorts of friends, it behooves Washington to lower its expectations and take a more transactional approach to enlisting cooperation, whenever possible, on a single issue or subsets of issues. A disappointed Saudi Arabia, for instance, might play ball with the United States on Syria — even as it opposes Washington’s policy in Iraq. Turkey could be convinced to better police its border in exchange for a U.S. policy shift on the Kurds, who have made rapid gains in northern Syria.

The biggest benefit of the Iran deal is the diplomatic process it created. The intense relationships that evolved over the course the negotiations can now be used to open conversations on other issues. Whether those conversations bear fruit is another matter — but history teaches us that personal trust among diplomats can change the direction on the ground.

It would be a mistake, however, to think of this agreement as an inflection point akin to the Camp David Accords between Israel and Egypt, which completely shifted the dynamics of the Middle East conflict. The Iran nuclear talks are more like the Madrid process, the breakthrough that lead to the Oslo Accords: a first diplomatic step that could, in turn, lead to other diplomatic steps. And like the Oslo Accords, it could still ultimately fail to accomplish any of its stated goals.

So let’s not overstate the impact of the agreement just yet. The agreement hasn’t yet given the world any tangible achievements, in the form of abated extremism or disarmed militants. What’s more, the Middle East remains on course for another decade of murderous warfare, deepening sectarian feuds, and destabilizing polarization. These are grim phenomena with inescapable and dangerous strategic consequences for Middle Eastern countries, global energy markets, and the security interests of the United States.

If the Obama administration hopes to change this reality, it will need to pressure every major player — both allies and adversaries — to shift course. Iran, the Syrian regime, and Hezbollah could be emboldened by the deal and tempted to double down on their current maximalist bets. Troublesome friends such as Israel, Saudi Arabia, and Turkey, meanwhile, have continually undermined U.S. aims in the Middle East and will do so with even more boldness as they try to derail the nuclear deal.

Washington is going to need to change the calculations of both groups, and it’s not going to be easy. The Obama administration will have to manage petulant allies enraged by the deal and persuade drifting fence-sitters like Turkey and Egypt to play a more constructive role in breaking regional stalemates.

It will also have to defy recent history by rolling back Iranian influence at a time when Tehran will be motivated to try to expand its reach. Iran, after all, already successfully expanded its reach through militant proxies and tightened relations with key Arab allies even during the period when sanctions crippled its economy. With a deal concluded, Tehran won’t walk away from its achievements. If the nuclear negotiations were grueling, imagine how hard it will be to pressure Iran’s supreme leader, Ayatollah Ali Khamenei, to sacrifice a material alliance with Syria, Iraq, or Hezbollah.

For years, Obama administration insiders have quietly spread the word that the president wasn’t tuned out on the Middle East. Instead, they argued, he was following a strategic order of operations. The first step was trying to seal a nuclear deal with Iran, the regional tiger, and then systematically deal with the region’s instability, proxy wars, and sectarian strife.

The coming months will test that claim. If Obama does in fact have a plan to use an Iran deal as the cornerstone of a new regional order, the real work begins now, and it will be messy. The dirty business of superpower realpolitik, a combination of muscle and diplomatic savvy, comes next. It’s what the United States should have been doing all along. The Iran deal gives it a chance to reboot and get it right.

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