When you see a glaring sign of negligence, it’s often a strong indicator of sloppy ignorance elsewhere.

Such is the case with President Obama and the burgeoning spy scandal in Germany. Astonishingly, it’s not Russia or China where we’re ensnared in an embarrassingly public spat over CIA activity. It’s our close allies in Berlin who are outraged over the pursuit of two alleged spies in the upper echelons of the German defense and intelligence ministries.

The most outrageous aspect of the kerfuffle is that Obama had no idea, apparently, that all this was going on. This is a president who must now confront claims that the U.S. has been tapping the phone of German Chancellor Angela Merkel — and then try to address the world’s business with her over the phone.

Now, Merkel is kicking America’s top spy out of her country. In recent years, not all Americans have been captivated by red-meat Republican charges that Obama mistreats our allies. That’s now likely to change.

Obama’s humiliation over the spy ordeal is a cautionary tale about the perils of unbound federal power.

Almost everyone agrees that a robust spy operation is important to national security. Obama, however, has overseen an unprecedented explosion in clandestine monitoring. Defenders have urged Americans to accept that some reductions in liberty are worth the gains that blanket intelligence gathering earns us. But operations conducted by unaccountable bureaucrats have a tendency — long demonstrated in domestic affairs — to erupt into unintended consequences.

Even so, in Germany, surveillance run wild created a climate of suspicion that directly fueled Berlin’s fury. Instead of lashing out at the handful of individuals at the CIA who blew their operations, Germans are lashing out at the vast, impersonal surveillance machine.

Germans aren’t alone in this regard. They’re joined by millions around the world and right here at home. Obama can’t possibly wish for that fury, distrust and distaste to define his legacy. He’d better do something about it — before the task falls to the next president.