NEW YORK ― The last-minute agreement between Russia and the United States to put Syria’s chemical weapons under international control gives the West, which had run out of good options, a second chance to reach what always should have been its strategic goal: peace in Syria and an end to its people’s suffering.

Russian Foreign Minister Sergei Lavrov took advantage of Western leaders’ failure to formulate a clear central objective. Did they hope to end Syria’s civil war by forcing a military stalemate, or to bring about the demise of President Bashar al-Assad’s regime? Did they want to strengthen international law barring the use of chemical weapons, or to send Iran a signal about their determination to enforce “red lines”?

The Russian proposal forced the West to choose prohibition of chemical weapons as its immediate goal. Given that this is one of the few areas of possible agreement in the United Nations Security Council, it is a good starting point to repair badly damaged relations among the Council’s five permanent members (China, France, Russia, the United Kingdom, and the U.S.). Of course, the deal may prove to be little more than a diversion, breaking the momentum toward military action but failing to achieve its goal. Its implementation will be a test of Russia’s good faith.

For their part, Western countries must avoid the traps of the difficult negotiation process that the deal demands, without losing sight of their strategic goal of ending the conflict. The complex process of securing and destroying Syria’s chemical arsenal promises to be next to impossible in the midst of a civil war. To succeed, Western leaders must reframe their approach to the Syrian endgame, rejecting the assumptions that have shaped their policies since the beginning of the crisis.

The West’s fundamental mistake has been consistently to underestimate the Assad regime’s resilience. Despite its brutality, the Assad government retains a substantial base of supporters who are willing to fight to the death to prevent the regime’s collapse. Indeed, many Syrians believe that they have no future if Assad’s government collapses ― a belief that has been reinforced as the civil war’s dividing lines have become increasingly sectarian. With regime supporters’ physical survival seemingly at stake, the expectation of a quick collapse was illusory.

More problematic, the West’s loud calls for Assad’s exit from power, though now muted, have given false hope to the opposition, while Russia has been hiding behind the rhetoric of a “Syrian-led process” to avoid confronting its international responsibilities. But a diplomatic solution guided by the Security Council’s permanent members is the only credible path to peace. The alternative ― an attempt at negotiation between Syria’s government and an increasingly fragmented opposition ― would serve only to prolong the war and raise the death toll.

Likewise, the West must recognize that reconciliation in Syria will be impossible without reconciliation between the Sunni and Shia regimes in the wider region. Several of the Sunni-ruled Gulf monarchies view Syria’s crisis and the prospect of Assad’s demise as an opportunity to compensate for Iraq’s rapprochement with Iran following the fall of Saddam Hussein’s Sunni regime and the emergence of a Shia-led government.

A year ago, the U.S., the U.K., and France appeared to side with Saudi Arabia when they rejected former U.N. Secretary-General Kofi Annan’s request that Iran be invited to the first attempt in Geneva to negotiate a settlement of Syria’s civil war. They probably feared that Iran’s participation in the talks would enable Iranian leaders to link efforts to end the Syrian crisis to negotiations over Iran’s nuclear program, enhancing their ability to resist international demands that the program be terminated.

But, while Iran’s direct involvement in Syria ― where its own Revolutionary Guards, along with its Lebanese proxy, Hezbollah, are fighting in support of Assad ― is part of the problem, a long-term solution is virtually impossible without Iranian participation. Indeed, the Middle East cannot achieve long-term stability while Iran is excluded from negotiations and the Shia-Sunni schism is allowed to deepen. Although it is too soon to tell what, if anything, will come of the current diplomatic charm offensive by Iran’s more moderate new president, Hassan Rouhani, it might herald an important shift in Iranian policy that could ultimately enable regional reconciliation.

With the entire Middle East undergoing a generational transformation, regional challenges cannot be addressed separately. Only a unified, comprehensive approach can manage the forces driving momentous change in the Middle East, prevent outside powers’ rivalries from complicating the situation further, and ensure a peaceful outcome. With emerging regional powers increasingly challenging the capacity of the Security Council’s permanent members to shape events in the Middle East, there is no time to waste.

The West’s lofty and self-serving rhetoric has not helped to end Syria’s conflict; it may even have made the situation more dangerous. Although the Russian initiative is not without pitfalls, it could be a crucial launchpad for more serious and constructive engagement with Syria ― and with the rest of the Middle East.

By Jean-Marie Guehenno

Jean-Marie Guehenno, former deputy joint special envoy of the United Nations and the Arab League for Syria, is professor of professional practice at Columbia University’s School of International and Public Affairs. ― Ed.

(Project Syndicate)