In Europe America's friends are furious, in the Middle East they are mystified, and in the Pacific they are merely puzzled.
Mounting questions over the direction of US foreign policy and sweeping espionage operations are threatening to undercut the Obama White House's claim to have mended relations with key allies that frayed under President George W. Bush.
The world is also looking on in alarm at political dysfunction in Washington and wondering whether it will curtail America's global role: Secretary of State John Kerry warned this week that US partners were asking, "Can we be counted on?"
President Barack Obama, already beleaguered over the chaotic rollout of his healthcare law, is struggling to deal with explosive new leaks from secrets scooped up by fugitive analyst Edward Snowden.
European publics that once swooned over the president are fuming at claims the US National Security Agency logged details of millions of their phone calls, and even apparently tapped the phone of German Chancellor Angela Merkel.
Heather Conley, a former deputy assistant secretary of state for Europe and Eurasia in the Bush administration, said the White House response had done little to placate its allies. "Their approach has led the [European] leaders to up the volume because we are not understanding how significant this issue is for public opinion," said Conley, now with the Centre for Strategic and International Studies.
In Washington some officials privately disdain Europe's fury as overly theatrical - because some of the outraged governments are partners in counterterror spying themselves.
"Everyone spies on everybody," Republican Senator Marco Rubio told CNN. "These leaders are responding to domestic pressures. None of them are truly shocked."
With Europe and the US bound by cultural, political and military ties and security vulnerabilities, it is unthinkable the alliance will buckle. But it is also clear that trust in the US among key allies has been undermined in a way that is forcing the hands of European leaders.
This explains unusually blunt readouts by aides to Merkel and French President Francois Hollande of their bosses' calls to Obama over the affair this week. Some US foreign affairs experts fret that the controversy could limit the political space allied leaders have to back key US foreign policy priorities, including a proposed Transatlantic Trade and Investment Partnership (TTIP).
Already the European Parliament has cast a non-binding vote to freeze a data exchange agreement with Washington on financial transactions, which intelligence agencies use to trace terrorist financing.
So far Washington's public statements are mostly notable for a lack of contrition. A statement by Obama spokesman Jay Carney that Washington is not spying and will not spy on Merkel's communications outraged Germans with the implication it had done so.
Obama, who has ordered reviews into the scope and breadth of US surveillance activity, is yet to comment publicly on the Merkel allegations.