LONDON--There was a telling moment in last Saturday night's Republican presidential debate that says a lot about America's misadventures in the Middle East over the past 15 years. Donald Trump, the real estate developer and current front-runner who has done everything from calling for a ban on Muslim immigrants to ridiculing the war record of Senator and former prisoner of war John McCain, finally did something to cause the Republican establishment to turn on him. Questioned about the presidency of George W. Bush, Trump said that the Bush Administration "lied" its way into the Iraq war by hyping weapons of mass destruction; called the invasion itself a "disaster;" and reminded the audience that "the World Trade Center came down" on Bush's watch. It was too much for the South Carolina audience, which booed him, and the other candidates, who unloaded on him. The irony is that the breaking point for Republicans was hearing Trump say something that was true.

The first step to solving a problem is to admit that we have one. It's time to admit what we all know to be true: American policy in the Middle East over the past 15 years has made a bad situation worse. In fact, for all intents and purposes, America no longer has a Middle East policy, at least not one grounded in today's reality. If the next President hopes to make the world safer, the United States needs to embrace a foreign policy that recognizes that the Cold War is over and deals with the Middle East as it is today - not the way it used to be.

It's not just Republicans who are stuck in denial. Supporters of President Barack Obama assert that he has done what he set out to do in the Middle East, from bringing U.S. troops home from the wars Bush started in Iraq and Afghanistan, to killing 9/11 mastermind Osama bin Laden, to striking a deal to limit Iran's nuclear capabilities. Yet, Democrats seem indifferent to Obama's policy of doing nothing in the region since Egyptians forced the resignation of long-time U.S. ally, President Hosni Mubarak, five years ago last week. They seem convinced that everything that has happened since has had little to do with Obama's stated policy of "leading from behind" - not the collapse of Libya, Yemen, and Iraq; nor the ruin of Syria; nor the rightward drift of Israel; the implosion of the Palestinian Authority; the Islamization of formerly secular ally Turkey; the horrific spread of the Islamic State; the Iranian takeover of governments in Beirut, Damascus, Baghdad, and the Yemeni capital of Sana'a; or the reassertion of Russian power in the region for the first time in decades.

But the reality, as journalist and Middle East scholar Yaroslav Trofimov has written, is that "since ... 2011, America's ability to influence the region has been sapped by a growing conviction that a risk-averse Washington, focused on a foreign-policy pivot to Asia, just doesn't want to exercise its traditional Middle Eastern leadership role anymore." As James Jeffrey, a former U.S. Ambassador to Iraq and Turkey, told Trofimov last fall, neither allies nor adversaries believe the U.S. will use its muscle "to protect our friends." Because of this, "nobody is willing to take any risks."

In a perverse way, Bush's misguided adventurism and Obama's indifference have combined to make real the goal of uniting "Muslim and non-Muslims" that Obama articulated in a 2009 speech in Cairo: across the region, friends and foes alike are united in saying they don't trust America, they don't fear America, and they don't believe a single word that America has to say.

It wasn't always this way. From the end of World War II until the fall of the Berlin Wall, American policy was clear: containment. We supported major regional powers that opposed Soviet expansion - namely, Turkey, Israel, Saudi Arabia and Iran, with Egypt taking Iran's place after the Islamic Revolution 1979 - and together, we held in check those nations (Iraq, Syria) backed by Moscow. After the Soviet Union collapsed, we shifted our policy to encourage peace between Israelis and Palestinians, worked to contain Iran and Iraq, and continued to support Arab regimes that supplied the U.S. with oil while overlooking their human rights abuses.

With the invasion of Iraq, all of that changed. The U.S. shifted from a policy of containment to an ambitious - some say "delusional"- policy of direct regional transformation. America had no plan for who should rule Iraq after Saddam Hussein, a Sunni, fell. Those who took his place, all Shiite, turned the post-war period into a Sunni witch hunt, radicalizing Saddam's former Sunni soldiers into ISIS warriors. In the process, the centuries-long conflict between Sunni and Shiite Islam moved to center-stage, driven by Sunni Saudi Arabia and Shiite Iran, while the Israeli-Palestinian conflict became a sideshow. Meanwhile, Obama has, as scholar Steven Cook writes, "erred in a variety of ways, whether it has been ... unwillingness to consider intervention in Syria when it might have made a difference, declaring phantom 'red lines', getting roped into a Libyan intervention ... or placing the United States in a position where it needs a nuclear agreement with Tehran more than Iran needs a nuclear agreement with Washington."

The next President needs a new playbook for the Middle East - one grounded in three new realities that are shaping the future of the region today.

First, Islamist terrorism, starting with ISIS, is the most dangerous threat the West faces today and defeating it must be the centerpiece of our policy going forward.

In the past year, brutal Islamist attacks from Paris to Jakarta to a Russian jetliner to San Bernardino, California have signaled a tactical change on ISIS's part, making it clear that the group's attacks are now going global. If ISIS is allowed to consolidate its gains in Syria or Iraq, the threat to U.S. security and regional allies will increase considerably. Just as the litmus test during the Cold War was "with us or against us" in the fight against communism, the U.S. should work to unify all those who oppose Sunni fanatics in ISIS and other Islamist militant groups under one strategy. If that means partnering with Russia through the United Nations, supplying the Kurds in Iraq and Syria, defending Iraqi Sunnis from Shiites in Baghdad, or engaging with Iran's Revolutionary Guard to defeat ISIS fighters - we should do what it takes.

Second, the United States should accept that the region is shifting back to more natural borders and not try to maintain the artificial lines drawn by the West a century ago.

The Middle East is no longer the Middle East that exists today on maps. The artificial Sykes-Picot line drawn by Britain and France to create Iraq and Syria in 1916 is already being worn away. Iraq has largely reverted to the three provinces - one Shiite, one Sunni, one Kurd - that existed during the Ottoman empire. An independent Kurdistan could very well become America's greatest ally in the region as Kurds continue to defeat ISIS with regularity. Sunni Muslims could run a new country that includes part of present-day Iraq and a pluralistic Sunni-majority Syria. Just as the civil war in the Balkans in the 1990s saw the region revert to more natural borders, America should let the Middle East evolve back to its natural lines and spheres of influence.

Third, some of America's long-time friends are no longer acting like friends, and we should stop treating them as friends.

It's time for America to look beyond history to see our longtime allies for what they are now. Saudi Arabia, which America no longer needs for oil, has spent billions building anti-Western madrassas across the globe to create the next generation of jihadists while funding Islamist terrorist groups from ISIS to Al Qaeda. Our once secular NATO ally, Turkey, is being transformed under President Recep Tayyip Erdogan into one of the most virulently Islamist, authoritarian countries in the region, aligning itself with Hamas while opposing U.S. interests at every turn. Pakistan will soon have the world's third-largest nuclear arsenal while providing a safe haven to Islamist terrorists. Even Israel continues to build settlements at an alarming rate in Palestinian territories while openly challenging U.S. leadership. It's time to say as clearly as possible: change your ways or the party is over - including all financial, military, and security support.

If the history of the Middle East has taught us anything, it is that nobody follows the sound of an uncertain trumpet. Somewhere between the incompetence of George W. Bush and the indifference of Barack Obama, the region stopped listening to America. It's not too late for the next President to regain America's historic leadership position in the Middle East. But it will only happen if we leave the Cold War playbook behind and see the new world for what it is - for good and bad.

Stanley Weiss, a global mining executive and founder of Washington-based Business Executives for National Security, has been widely published on domestic and international issues for three decades.