For 48 hours in Ankara, Turkey, it felt as though the world was moving on Donald Trump's timetable.

Markets lurched. NATO allies braced for confrontation. Ukraine searched for reassurance. Iran threatened to upend the agenda. One moment, leaders were preparing for diplomatic crisis; the next, they were describing a "love-in" with the very president many had feared would leave the alliance more divided than ever.

I've covered hundreds of major international events over my 25 years at CNBC — G7, G8 and G20 summits, OPEC meetings, climate conferences and multiple trips to Ukraine. But I've never witnessed such dramatic reversals of fortune, affecting so many global players, compressed into just 48 hours.

Think about everything that was in play. Iran. Russia's war in Ukraine. Greenland. European security. Spain's refusal to meet NATO's military spending targets. President Volodymyr Zelenskyy's uncertain standing with Washington. Every major issue seemed to converge on one summit — and every one of them ultimately revolved around the U.S. president.

To recount, every European NATO member — plus Canada — was effectively on trial coming into this gathering. Trump and Defense Secretary Pete Hegseth had again been aggressively criticizing NATO for its lack of support over Iran and for failing to spend anywhere near enough money on its own security.

In addition, the president took aim at Denmark yet again over its refusal to hand over Greenland for the greater good — whose greater good being a mildly contentious point — and, of course, Spain was getting both barrels for being even worse than the other 30 NATO partners in its military spending.

Zelenskyy was in town, once again to drum up NATO support. And let's be honest, he never really knows what kind of reception he's going to get from the Leader of the Free World.

Then came the absolute bombshell from Mr. Trump that he was done with dealing with the Iranians, done with the MOU and the ceasefire. Markets went south and oil went north.

At that point, the summit appeared to be heading toward confrontation.

And yet, then the optics changed on a dime. The mood changed just like that and suddenly love was in the air.

Even before the big final Trump press conference, world leaders were telling me in quiet asides that the meeting with Trump had gone brilliantly, that he had been very happy, that he had listened — actually listened — to every leader in the big closed-door pow-wow and had left in a good mood.

Hang on, was this the same Donald Trump who had been berating partners only hours earlier?

Yes, apparently so.

I wasn't so sure, but I heard it myself from the horse's mouth only hours later when, in front of a thousand journalists at his summit-closing press conference, the U.S. president confirmed the love-in was real.

Standing alongside Secretary of State Marco Rubio, Treasury Secretary Scott Bessent, Hegseth and Deputy Chief of Staff Stephen Miller, the president spoke of the "tremendous love in the room" during the leaders' meeting. "The unity was amazing," he said. "The love was pretty wild."

It was a remarkable turnaround from the public criticism Trump had directed at many of those same allies only hours earlier.

CNBC's Steve Sedgwick speaks with Finland's President Alexander Stubb at the NATO Summit in Ankara, Turkey.

Michael Green

The summit produced some clear winners and losers. Turkish President Recep Tayyip Erdoğan emerged stronger after hosting a smooth summit and appeared to move closer to securing U.S. approval for F-35 fighter jets.

Mark Rutte, the NATO secretary general, kept up the praise for Trump and, in doing so, helped keep the U.S. engaged with NATO, at least for now. Spain and Denmark, despite early assaults, came away without any major rebuke from the U.S. in Trump's closing press conference.

Another big winner must be Zelenskyy, who appears to have risen in the U.S. president's estimation as Ukraine has stabilized the battlefield and taken the fight deep into Russia despite the odds. The Ukrainian leader may even have secured a deal to produce Patriot missile systems — something Kyiv has long viewed as a priority.

Losers? Well, clearly Putin would have been unhappy with both the show of unity from NATO, its huge progress on defense spending and Ukraine's warmer reception from Trump.

And Iran? Well, that remains the big unknown.

I asked the U.S. president directly when I got the chance to fire a question at him: "What happens next if you really have given up on the ceasefire?"

His answer, I'm afraid, was opaque. He simply returned to the point that Iran would never have a nuclear weapon on his watch.

And perhaps that's the lasting takeaway from these extraordinary 48 hours.

The atmosphere inside NATO changed dramatically over the course of the summit, but the biggest questions remain unanswered. What happens next with Iran? Can the improved mood between Trump and NATO allies last beyond this meeting? And what does it ultimately mean for Ukraine?

Those questions matter far more than the political theater. But if this summit demonstrated anything, it is how quickly the geopolitical landscape can shift when Donald Trump is at the center of it. Allies, adversaries and markets alike are learning to adjust in real time.