President Barack Obama bade farewell to G20 leaders in Hangzhou, China, on Monday by reminding them they’re living in “turbulent” times — and he wasn’t kidding.

His valedictory Asia tour, which moved on to Laos later in the day, is unfolding amid diplomatic slights and great power rivalries that reflect the unstable nature of the world Obama will bequeath to his successor in January.

The controversies reflect the way international politics is now a stew of many competing, rising or resurgent powers that see fewer reasons to simply fall into line behind the United States than was the case following World War II and the Cold War. And it may suggest that foreign leaders are now just as interested in who will sit in the Oval Office next as they are in Obama as he heads for the exit.

Obama is not only confronting regimes in Russia, China and North Korea that are at times openly hostile to Washington — or at least willing to make clear they don’t want to play by its rules — but over the long weekend, he got headaches from allies as well, notably Turkey and the Philippines.

“Who is he?,” the fiery new President of the Philippines, Rodrigo Duterte, asked Monday at a news conference, referring to Obama. The Southeast Asian leader warned he would lash out if the US President raised extrajudicial killings in the Philippines’ new war on drugs in an anticipated meeting in Laos.

“I am a president of a sovereign state. And we have long ceased to be a colony of the United States,” Duterte continued. “Son of a b****, I’ll cuss you in that forum.”

It was a stunning show of disrespect for an American president. And though Obama shrugged off the comments from the “colorful” leader during his own news conference Monday, the White House later canceled his meeting with Duterte — and conferring instead with the President of South Korea.

Duterte is not the first erratic president of the Philippines, but his unpredictability and willingness to fan latent colonial resentment against the US represents an unwanted disruption for the White House at the end of Obama’s tenure. It comes in a regional cauldron where Beijing is making aggressive moves in the South China Sea and Southeast Asian nations are increasingly important to US efforts to rein in the rising power.

Obama had hoped to spend his final journey to Asia as president talking up the highlights of his pivot to the region. The fact sheet the White House put out at the conclusion of the G20 touted the economic progress under the eight years of the Obama presidency. And in one key outcome of the summit, he and Chinese President Xi Jinping formally agreed that both their nations would join the Paris Climate Agreement committing to cutting carbon emissions.

But that bright spot aside, his trip to China has offered reminders that since Obama took office in 2009 — and especially since Xi emerged as a nationalist leader after taking office in 2012 — Sino-US relations have worsened.

At the start of his trip, a logistical spat over missing airline airplane stairs needed for Obama to reach the red carpet at Hangzhou airport and verbal altercations between US and Chinese officials grabbed headlines.

At one point, a White House official warned a Chinese counterpart against restricting access of pool reporters under the wing of Air Force One, noting that it was, after all, a US plane. “This is our country,” the man yelled back.

Obama shrugged off that incident, too, acknowledging that disagreements over press access often arise with China but contending that they were not emblematic of the US-China relationship.

The Republican hoping to succeed Obama, however, took a much dimmer view of the episode.

“Can you believe that the Chinese would not give Obama the proper stairway to get off his plane – fight on tarmac!” Donald Trump tweeted.

Either way, the flap served as a symbol of the tensions over issues of sovereignty that can occur between an ascending authoritarian state and an established democratic superpower used to getting its own way — clashes that some analysts fear could play out on a geopolitical stage in years to come.

Another country that has expanded its power base by thumbing its nose at the United States — Russia — also grabbed the spotlight during the G20 summit. Obama and President Vladimir Putin were pictured on Monday locked in an unfriendly stare, clearly with little love lost between them.

“Typically, the tone of our meetings are candid, blunt, businesslike — and this one was no different,” was how Obama described it to reporters.

He referred to “gaps of trust” over Syria, warned that the US has “more capacity” both “offensively and defensively” when it comes to cyber espionage and stressed that the US has no intention of easing sanctions against Russia over its action in Ukraine.

The tough talks were a reminder that the “reset” of Russia relations that Obama pioneered at the start of his administration is now but a memory, while Putin has also taken advantage of chaos in the Middle East to reinstate Russian influence with Syria and Iran.

Obama also invested significant first-term political capital in improving relations with another foreign leader he met at the G20 — President Recep Tayyip Erdogan of Turkey — with whom tensions were on display in their joint appearance.

Even though Obama bemoaned the “terrible attempted coup” that failed to topple Erdogan in July, the Turkish President did not shy away from raising differences with the US in front of the press.

“All forms of terrorism are bad. All forms of terrorism are evil,” Erdogan said, then mentioned the names of a Kurdish group with which the US is allied in Syria but is regarded by Ankara as a terrorist organization.

As he headed to Laos, Obama professed to being undeterred by the unpredictable unfriendly international environment at the end of his presidency.

“I think we all to have recognize these are turbulent times. A lot of countries are seeing volatile politics,” he said at his news conference. “But then when you look back over the course of eight years, actually you find out things have gotten better.

“I tell my staff when they feel worn out sometimes that better is always good,” he added. “It may not be everything that needs to get done, but if it’s better than before we started, we’ll take it.”