Washington's most difficult overseas challenge is not Syria, Iran, Afghanistan, Libya, Egypt or Russia. Nor is it the serious foreign relations rift with Germany, caused by the revelation that the US has been spying on Chancellor Angela Merkel for several years.
Instead, the most significant hurdle for President Barack Obama in this, his turbulent second term, is to hose down the perception that his administration is perceived as the new Spy Central.
Even US Secretary of State John Kerry conceded on Friday that the spooks went too far. And German Foreign Minister Guido Westerwelle spoke for most of the world when he said that tapping Dr Merkel's phone is no way to fight terrorism.
So the assertion by the United States National Security Agency's (NSA) head, General Keith Alexander, at a public congressional hearing this week that the US was merely analysing metadata handed over by European allies raises a fundamental question. Quite simply, why did it take so long for this revelation to emerge?
Yes, every country has surveillance programmes - in a physical and a cyber sense - so what makes the US unique in this respect?
In part, it is because the world would not have known of its wide scope without the leaks in June this year from fugitive defence contractor Edward Snowden.
Add to that the fact that the US made several accusations this year about what it said was a sustained campaign of corporate and defence-related cyber spying by China.
It is now ironic that the gravity and reach of the US surveillance far outweigh its own allegations against Beijing.