After watching Presidents Barack Obama and Vladimir Putin working hard to look at ease in the United Nations spotlight while twirling through their dueling global gambols, a persistent question requires our attention.

It is one we’ve put off tackling for years and concerns the president we Americans like to call the “leader of the free world.”

Question: When was it that President Obama actually realized he really didn’t know what the heck was going on in the Arab world?

Answer: We have multiple options to choose from.

Maybe it was all the way back when events in Egypt made it clear that the Arab Spring was not destined to create a wave of democracy that would sweep across the still-despotic Middle East.

Maybe it was when he saw that following the deposal of Libya’s Moammar Gadhafi, the Arab Spring failed to produce a government of, by and for the Libyan people.

Maybe it was when the ultra-militant Islamic State terrorists — a force also called ISIS and ISIL that wasn’t even on Obama’s briefing pages and radar screens when he became president — suddenly emerged. And emerged victoriously in places where we didn’t even know they were a threat.

Obama discovered only a bit before we all did that ISIS was achieving stunning successes in Syria and Iraq and was even emerging as a potential threat within Turkey and inside Russia.

Maybe it was when departing United States troops were tiptoeing in combat boots through the sands of Iraq, and lo, Iranian military advisers were tiptoeing in. Iran’s rulers, who vilify America, just became the leading influence in the land that used to wage war on them. (See also: The land where thousands of Americans died and were gravely wounded to liberate Iraqis from Saddam Hussein’s dictatorship.)

Maybe it was when Obama tried to stand strong against Syria’s Bashar Assad, insisting the dictator was on his way out of Damascus.

When, as an afterthought in a long, rambling press conference answer, Obama drew his famous “red line” across Syria.

He warned that Syria would be crossing the line by using its chemical weapons inside Syria, or if it even just moved them. Did Obama have any idea what that meant he would do when (as expected) Assad or his generals used their chemical weapons?

Syria used its chemical weapons, Obama did nothing, and all the world saw an American impotence no one expected we’d ever see. Arab Gulf state leaders began asking journalists if they knew what America’s policy was.

In the Kremlin, Putin figured he knew. He concluded there was a world leadership vacuum and moved to fill it while team Obama was wondering what the “whoosh” they just heard was about.

The correct answer to our question could be any, or all, of the above. But clearly Obama now knows that he didn’t know what he needed to know. And didn’t know it when he needed to know it.

But perhaps he has also just figured out — perhaps too late, hopefully not quite — the one last thing he needed to know. That he has needlessly ceded leadership to Russia’s respect-craving president in that part of the Middle East. And, had Obama seized the opportunity, he could have put together a world coalition on Syria and the Middle East. And he might well have been able to do it in a way that could have eased other flashpoints that range from Ukraine to Afghanistan to even the nuclear agreement with Iran.

Putin has been desperately craving world respect ever since he chose to be militaristically assertive in Ukraine, thus jettisoning all the goodwill and global economic prospects he’d created by hosting the Olympics. He did that because he felt Ukraine dissed Russia by moving to ally with NATO, not Moscow.

But Putin has probably been open to a face-saving way back into global good graces. And a partnership in Syria with all the West to jointly defeat ISIS — and pressure Assad to stop killing his citizens — could probably have been forged.

But Putin has moved to seize the leadership opportunity Obama missed, forming his intelligence consortia with Iraq, Iran and Assad’s Syria.

Now it is uncertain how this will play out in Syria and the Middle East and around the world.

And inside the gates of Washington’s 1600 Pennsylvania Avenue, yet another president has created the geometrically confounding impression that he has somehow painted himself into a corner of his Oval Office.

Martin Schram is a columnist with Tribune News Service.