China has now assumed the mantle of fighting climate change, a global crusade that the United States once led. Russia has taken over Syrian peace talks, also once the purview of the American administration, whose officials Moscow recently deigned to invite to negotiations only as observers.
France and Germany are often now the countries that fellow members of NATO look to, after President Trump wavered on how supportive his administration would be toward the North Atlantic alliance.
And in the Israeli-Palestinian conflict, the U.S., once the only mediator all sides would accept, has found itself isolated after Trump's decision to declare that the U.S. recognized Jerusalem as the capital of Israel.
In his wide-ranging speech on national security last week, Trump highlighted what he called the broadening of U.S. influence throughout the world.
But one year into his presidency, many international leaders, diplomats and foreign policy experts argue that he has reduced U.S. influence or altered it in ways that are less constructive. On a range of policy issues, Trump has taken positions that disqualified the United States from the debate or rendered it irrelevant, these critics say.
Even in countries that have earned Trump's praise, such as India, there is concern about Trump's unpredictability — will he be a reliable partner? — and what many overseas view as his isolationism.
"The president can and does turn things inside out," said Manoj Joshi, a scholar at a New Delhi think tank, the Observer Research Foundation. "So the chances that the U.S. works along a coherent and credible national security strategy are not very high."
As the U.S. recedes, other powers including China, Russia and Iran are eagerly stepping into the void.
One significant issue is the visible gap between the president and many of his top national security advisors.
Trump's national security speech was intended to explain to the public a 70-page strategy document that the administration developed. But on key issues, Trump's speech and the document diverged. The speech, for example, included generally favorable rhetoric about Russia and China. The strategy document listed the two governments as competitors, accused the Russians of using "subversion" as a tactic and said that countering both rival powers was necessary.
Russia reacted angrily: America continues to evince "its aversion to a multipolar world," President Vladimir Putin's spokesman, Dmitri Peskov, said.
At the same time, Trump's refusal to overtly criticize Russia, some diplomats say, has emboldened Putin in his military actions in Ukraine, where Russian-backed rebels are battling a pro-West government in Kiev. Kurt Volker, the administration's special envoy for Ukraine, said that some of the worst fighting since February took place over the past two weeks, with numerous civilian casualties. Volker accused Russia of "massive" cease-fire violations.
Nicholas Burns, who served as a senior American diplomat under Republican and Democratic administrations, said the administration's strategy was riddled with contradictions that have left the U.S. ineffective.
Trump "needs a strong State Department to implement" its strategy, he said. "Instead, State and the Foreign Service are being weakened and often sidelined."
Trump's "policy of the last 12 months is a radical departure from every president since WWII," Burns said in an interview. "Trump is weak on NATO, Russia, trade, climate, diplomacy. The U.S. is declining as a global leader."
The most recent example of U.S. isolation came with Trump's decision to formally recognize Jerusalem as the capital of Israel, delighting many Israelis, but angering Palestinians and reversing decades of international consensus.
On Thursday, an overwhelming majority of the U.N. General Assembly, including many U.S. allies, voted to demand the U.S. rescind the decision.
For the last quarter-century, successive U.S. governments have held themselves up as an "honest broker" in mediating peace between the Israelis and Palestinians. Trump insisted he is not giving up on a peace deal, but most parties involved interpreted his announcement as clearly siding with Israel.
"From now on, it is out of the question for a biased United States to be a mediator between Israel and Palestine," Turkish President Recep Tayyip Erdogan said at a summit of more than 50 Muslim countries that he hosted in Istanbul. "That period is over."
Daniel Kurtzer, a former U.S. ambassador to Israel and Egypt under Presidents Clinton and George W. Bush, said that if a peace deal is to be made now, "it won't be from American policy."
"Trump took himself and the administration out of the peace process for the foreseeable future," he said.
Trump had boasted of his ability to convene Muslim leaders during his trip to Saudi Arabia in May, but that would seem far less possible today. In Jordan, arguably Washington's closest Arab ally in the Middle East, government-controlled television has started 24-hour broadcasts of invitations to follow a Twitter account whose hashtag roughly translates as "Jerusalem is ours … our Arabness."
Regional leaders and analysts also say that for all of Trump's tough rhetoric, they see few concrete steps by the U.S. to counter Iran's steady expansion of its military, economic and political influence, a perception that Iranian leaders are happy to exploit.
"Trump is ranting and making empty threats," said Hamid Reza Taraghi, a conservative Iranian politician with close ties to Iran's supreme leader, Ayatollah Ali Khamenei. "Russia, China and Iran are gaining ground in the Middle East, and America is losing ground and influence."
That view is also shared by Iranian moderates, with whom the Obama administration thought it could work.
"The reality on the ground in the Middle East is that the American administration has failed to form an efficient coalition against its self-proclaimed enemies," said Nader Karimi Juni, an independent Iranian analyst who writes for reformist dailies and magazines.
"Now Russia is celebrating its victory in Syria, and America is watching as an onlooker," Juni said.
In Syria and Iraq, the U.S. under Trump has succeeded in helping its allies drive Islamic State militants out of their strongholds. But Washington has opted to take a back seat in the other conflicts roiling the two countries.
This month, another round of U.N.-mediated and U.S.-backed peace talks on Syria wrapped up in Geneva without any progress. Instead, a Russia-led process is gaining traction.
Even some longtime opponents of Assad quietly acknowledge that Sochi, the Black Sea resort where Russia aims to convene a "Syrian people's congress" next year, and not Geneva, will be the focus of efforts to bring an end to the war.
Trump has won praise in parts of South Asia, a region his team has re-dubbed the "Indo-Pacific" and where it is favoring India and Afghanistan over Pakistan. The administration has asked Congress for $350 million in aid to Pakistan for 2018, not quite one-tenth the amount Washington provided five years ago.
Afghan officials say they are encouraged by Trump's renewed pressure on neighboring Pakistan to take "decisive action" to stop militant groups operating from its soil.
"Our partnership, which reflects a renewed U.S. commitment, will set the conditions to end the war and finally bringing peace to Afghanistan," Afghan President Ashraf Ghani's office said in a statement.
But even there, officials say they worry that Trump's bellicose rhetoric will strengthen China's status as a power broker.
China has also benefited from Trump's refusal to join other nations to work against climate change. Even as Trump removed climate change from the list of threats menacing the United States, China announced it would begin phasing in an ambitious program to curb carbon emissions by establishing the world's largest market for trading emissions permits.
Trump was not invited to an international climate summit hosted earlier this month by French President Emmanuel Macron because of his decision to pull the United States out of 2015 international climate deal.
"You cannot pretend to be the guarantor of international order and get out of [an accord] as soon as it suits you," Macron told France 2 TV.