Trump's first 100 days: 'America First' president is overturning world order

In the chaotic first 100 days since President Donald Trump returned to office, he has waged an often unpredictable campaign that has upended parts of the rules-based world order that Washington helped build from the ashes of World War II.

He has launched an unprecedented global tariff war and slashed US foreign aid. He has disparaged NATO allies and embraced Russia's narrative about its invasion of Ukraine. And he has spoken about annexing Greenland, retaking the Panama Canal and making Canada the 51st state.

"Trump is much more radical now than he was eight years ago," said Elliott Abrams, a conservative who served under Presidents Ronald Reagan and George W. Bush before being appointed US special envoy on Iran and Venezuela in Trump's first term. "I have been surprised."

Trump's second-term "America First" agenda has alienated friends and emboldened adversaries while raising questions about how far he is prepared to go. All this comes amid what the Republican president's critics see as signs of democratic backsliding at home that have raised concerns abroad. 

"What we're seeing is a huge disruption in world affairs," said Dennis Ross, a former Middle East negotiator for Democratic and Republican administrations. "No one is certain at this point what to make of what's happening or what will come next."

This assessment of Trump's shakeup of the global system comes from Reuters interviews with more than a dozen current and former government officials, foreign diplomats and independent analysts in Washington and capitals around the world.

Many say that while some of the damage already done could be long-lasting, the situation may not be beyond repair if Trump softens his approach. He has already backtracked on some issues, including the timing and severity of his tariffs. But they see little chance of a dramatic shift by Trump and instead expect many countries to make lasting changes in their relationships with the US to safeguard against his erratic policy-making.

The fallout has already begun.

Some European allies, for instance, are looking to boost their own defence industries to reduce reliance on US weapons. Debate has intensified in South Korea about developing its own nuclear arsenal. And speculation has grown that deteriorating relations could prompt US partners to move closer to China, at least economically.

The White House rejects the notion that Trump has hurt US credibility, citing instead the need to clean up after former President Joe Biden's leadership on the world stage.

"President Trump is taking swift action to address challenges by bringing both Ukraine and Russia to the negotiating table to end their war... and protecting American workers by holding China accountable," White House National Security Council spokesman Brian Hughes said in a statement.