Les Gelb never grew tired of the Middle East. He rejected the narrative that American power is in such decline that it can do little good in the region, as well as the view that the Middle East is nothing more than an inextricable morass of danger and disappointment.

Les focused on how creative power and diplomacy can exploit—and create—opportunities. Finding those opportunities is his lasting challenge to us, and is now more urgent than ever.

By 2009, Les would write in Power Rules that America’s lack of strategy in the Middle East had landed us in quicksand in the desert. There was the 2003 invasion of Iraq—with more than 200,000 American service members tied down there and in Afghanistan—precluding the United States from tackling rising threats elsewhere in the world. And there was a paralyzing paranoia that Iran was a great threat rather than what Les deemed to be a third-rate power: Despite Iran’s pursuit of nuclear weapon capability, support for Hezbollah, Hamas, and terrorism, and rising conventional power, Iran did not seriously challenge America’s place in the world and could be effectively dealt with through savvy power and diplomacy.

Les insisted that America could rebound from the failure in Iraq. He believed that the way George W. Bush convinced Muammar Qaddafi to surrender Libya’s nuclear weapons could be a blueprint for negotiations with Iran, that the combination of ambiguity and tenacity seen during the Good Friday Accords in Northern Ireland could inform how to approach the Arab-Israeli conflict, and that Richard Holbrooke’s style of diplomacy in the Balkans could be a roadmap for a federated structure in Iraq.

Les was right that the Middle East holds unexplored opportunities. Seizing them requires not just tough action, but a strategy for the next three moves ahead. Les supported taking those who do America harm off the battlefield. One of the authors of this article, Matt Spence, was in the Situation Room with President Obama during the operation that killed Osama bin Laden and spoke to Les afterwards. “It’s a whole new world,” he quoted me saying in a column he wrote soon after (of course, without telling me he would). But he also reminded me that the most important part is what happens next. Just as killing bin Laden did not defeat al Qaeda, so too the killing of General Qassim Suleimani is less important than the strategy for how to address Iran during what comes next.

Of course, at the time he wrote Power Rules, Les could not anticipate that three major shifts would reshape the region: the Arab Spring and resulting tumult in Syria, Libya, Egypt, and Yemen; the rise of ISIS from the shards of Iraq; and—most consequentially—the election of Donald Trump.

Every new U.S. President takes office thinking he can do things differently, and quickly learns that there are no simple solutions to these complex equations. The Middle East leaves us, as Les put it, with “not great—but plausible policies” to pursue.

U.S. policy in the Middle East today—if one can even call it that—lacks Les’s vision for finding opportunities. Instead, it creates problems but makes little effort to solve them: rejecting a nuclear agreement with nothing in its place, threatening war with Iran only to back away inches before the ledge—surprising our own military and squandering our credibility; taking Soleimani off the battlefield with no game plan for what comes next; and equating support for America’s allies in the region with writing blank checks for Israeli Prime Minister Benjamin Netanyahu or Saudi Crown Prince Mohammed bin Salman. Les would have an even longer list of missed opportunities, and a few scathing phrases to go with it.

We can hear Les haranguing us to seize the opportunities that President Trump is missing: common Israeli and Sunni Arab frustrations with Iran that could be a bridge for reform; a rising generation in the region, where 70 percent of the population is under the age of 30 and eager to build an economic agenda in the region; and the rise of a next generation of leaders who are half the age of the kings and emirs they will replace, and who have the potential to pursue political and economic reforms that are decades overdue.

Les hated watching policy in search of a strategy. He let those of us who served in government know it, even when we did not want to hear it. Les was opportunistic and optimistic, but never naïve. For all the ways in which Trump has squandered the potential of U.S. power in the Middle East, we can hear Les’s call to us today: There are still opportunities ahead to rebuild what Trump has torn down.