On a trip to Manila in 2014, President Obama was pressed by reporters about the "weakness" of his foreign policy, especially in Syria and Ukraine.
He responded sharply: "Why is it that everybody is so eager to use military force after we've just gone through a decade of war? Many who were proponents of . . . a disastrous decision to go into Iraq haven't really learned the lesson of the last decade, and they keep on just playing the same note over and over."
That response (later abbreviated into "don't do stupid stuff") summarizes the core of Obama's foreign policy - and where it went wrong.
Whether the problem was Syria, Ukraine, or the South China Sea, the task was to avoid the mistakes George W. Bush made by sending troops to Baghdad. Americans elected Obama because they were tired of foreign conflicts.
So far, so good, but the premise was insufficient. A robust foreign policy didn't have to repeat the military adventures of the Bush years, and projecting strength didn't require sending in the Marines.
Instead, the way Obama chose to retrench convinced friends and adversaries that America was in retreat - and bad actors rushed to fill the vacuum. The results weren't what Obama intended or expected. But, then, the world of 2017 isn't the world he envisioned in 2008.
Ironically, Obama was never opposed to using force abroad if there was no other option. Indeed, he shocked the crowd at his (premature) Nobel Peace Prize ceremony by making that clear.
But the new president sought to off-load the global policing role America had been carrying. He assumed that allies would and could take on some of those duties. "Those who used to chastise America for acting alone in the world cannot now stand by and wait for America to solve the world's problems alone," he advised in his first address to the U.N. General Assembly in 2009.
He also assumed that, if he engaged longtime adversaries, including Russia, Iran, and China, he could convince them it was in their interest to play by global rules. Both of Obama's key assumptions proved incorrect.
Allies proved incapable of taking on the role Obama hoped for, without a firmer U.S. leadership component. In Iraq, the president's eagerness to withdraw on a 2011 deadline (set by the Bush team) meant the Obama administration paid too little attention to a budding ISIS insurgency in Mosul that might have been nipped early. In Afghanistan, Obama was so frustrated by the Karzai government that he set a public deadline for troop withdrawal - which inspired the Taliban to resist a peace deal.
In both cases, the administration has had to return U.S. military trainers and special forces to deal with continuing terrorist threats.
Then, in Libya, the president's hope that NATO allies would do the nation-building after the removal of Moammar Gadhafi, proved unfounded. After Libya, Obama concluded that intervention - urged on him by the Europeans and Arab allies - was a mistake that shouldn't be repeated in Syria.
Fast-forward to the bleeding Syrian disaster, which may define Obama's foreign-policy legacy. We will never know whether U.S. help to (still existent) moderate Syrian rebels in 2012 might have forced Bashar al-Assad to the negotiating table. (I still believe so.)
But we do know that Obama's last-minute failure in October 2013 to follow through on his own red line - to punish Assad for the use of chemical weapons - convinced the world, including Russia and Iran, that he was weak-kneed. Even his use of drones, and the belated U.S. buildup of Iraqi forces to take on ISIS, hasn't changed that impression.
Vladimir Putin no doubt included that in his calculations when invading Crimea in February 2014. While Obama should get credit for mobilizing sanctions against Moscow, he might have forestalled Putin's incursion into eastern Ukraine with immediate defensive aid to Kiev. A stronger U.S. stand in Ukraine might have made the Russian leader think twice before starting his military involvement in Syria. And so on.
The bottom line: Obama's dream of an interconnected, rules-based world adhered to by allies and adversaries proved to be mostly a fantasy. (I say "mostly," since Obama made headway on a climate-change treaty and Asian nations lined up with Washington on the TPP trade deal, which was meant to buffer them against Beijing. Both these gains will disappear under President Trump.)
However, that rules-based world is crumbling under pressures of globalization, and a return of geopolitics. China took notice of Russia's successful aggression and built up shoals in the South China Sea. Iran has signed a (useful) nuclear accord but won't stop destabilizing the Middle East. Terrorism will not die after ISIS does.
As a result, allies in Europe, the Mideast, and Asia are now desperately looking to Washington to help them fight back against Russian, Chinese, and Iranian pressures. They may finally be ready to share more of the burden, militarily and financially, because the world has become so scary.
It will be tragic if Trump - handed this opportunity - continues to disdain the European Union, rebuff NATO, and embrace Russia in the illusion that Moscow will act as an ally. And it is foolhardy for him to undervalue U.S. alliances in Asia.
Obama's error was to draw the wrong lesson from the Iraq disaster, interpreting it as a sign the United States must withdraw from paramount global leadership. But a Trump America First strategy will compound that error. Washington is doomed to lead or - if it no longer has the will or wallet - suffer the consequences at home and abroad.