On the back foot at hearings on Capitol Hill, America's intelligence chiefs tried to disarm the bomb created by the eavesdropping on Angela Merkel's phone by countering that the US has spied on foreign allies for decades and its allies have responded in kind.
The closely watched and sometimes tense hearings opened as pressure continued to mount on the White House and Congress explicitly to ban the monitoring of leaders of friendly countries by the National Security Agency, and instigate broader reforms to curtail its reach and increase its accountability.
National Intelligence Director James Clapper defended the NSA's programmes. "To be sure, on occasion we have made mistakes," he said.
As for spying on foreign leaders, he said it was "kind of a basic tenet" of US intelligence-gathering to find out their intentions and ensure that "what they are saying gels with what's actually going on". Asked if allies spy on US officials, he replied, "Absolutely."
Democrat legislators on the intelligence panel pressed Clapper and General Keith Alexander, the director of the NSA, and voiced wide misgivings as Washington grapples with growing anger from foreign allies, notably Germany amid reports the US began tapping the Chancellor's phone in 2002.
Part of the response took the form of hand-wringing about Edward Snowden, the former NSA contractor who has been the source of most of the recent revelations. "He did get great access to what we'll call the core capabilities we have ... and he took a lot of that," Alexander confirmed, adding the damage was being made worse by the way it has been "dribbled out".
"It's being done in a way that would cause maximum harm. I don't know why they would want to harm our country. But that's what's being done. And our allies."
Both Alexander and Clapper concurred quickly when asked by Republican congresswoman Michele Bachmann if they considered Snowden a traitor.
Yet, in a reversal of one part of the narrative of recent days, US officials pushed back against reports that the NSA had been sweeping up data on millions of phone calls made in France and Spain, asserting rather that those countries' own domestic intelligence agencies had been gathering the information - in war zones and areas outside their borders - and then sharing it with the NSA.
In his testimony, Alexander called "absolutely false" media reports about the collection of phone "metadata" - meaning items like numbers dialled, locations calls are made from and duration of calls - in France, Germany and Spain. He said the NSA had received data provided by Nato partner nations.
Republicans on the panel, including chairman Mike Rogers, attempted to shield the NSA and cautioned against legislation that might hobble its ability to keep Americans safe. "We can't ask the FBI to find terrorists plotting an attack and then not provide them with the information they need," he said, adding: "This is the time for leadership, it is not a time to apologise."
Separately, US officials were cited by Reuters revealing that Obama recently ordered the NSA to curtail its spying on foreign missions at the UN headquarters in New York.