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.