That question might sound counterintuitive, even cynical, a sign of the depth of Americans' hubris that we would even consider it. After all, friends don't spy on each other, right? But I'm going to let you in on a little secret: The international system is, and always has been, inherently adversarial, even among allies. To paraphrase the 19th-century British statesman Lord Palmerston, countries don't have friends, they have interests. Spying on friendly foreign nations does not actually violate the standard practices of international relations and in many ways is consistent with those norms. The close U.S. allies France and Israel are particularly known for it. Still, something as explicit as tapping Merkel's cellphone is a big and legitimately surprising step, one that may well go too far. Here is an evaluation of the pros and cons involved that may help clarify why the United States would decide to take such a step.
The simplest case for spying might be that the United States and Germany, despite being allies, still compete with one another, sometimes on quite substantive issues. If spying can give them a leg up on those issues, then aren't their leaders obligated to sanction it? President Obama's job, after all, is to further American interests, Merkel's to further German interests. Those conflict more than you might think; when they do, both leaders are potentially better served if they spy on the other.
In 2011, for example, Obama wanted to intervene in Libya, but Merkel did not and could have used her substantial influence in Europe to reduce NATO's participation. Ultimately, Germany was alone among Western nations in opposing the U.N. resolution on Libya and nearly alone in not providing military resources for the intervention. Merkel ended up coming under political pressure at home for the move. Washington and Berlin have also clashed over how to manage the euro-zone crisis, the resolution and progress of which have far-reaching implications for the German and U.S. economies. If dropping in on Merkel's phone calls can help the United States safeguard its economic and national security interests, that would seem to be a strong argument for doing so.
The case may be even starker with France, another major target of recently revealed NSA spying whose leaders have expressed official outrage at the surveillance. It's easy to forget today that in the 1960s, France made several provocative breaks with the American ally that had liberated its capital just two decades earlier. President Charles de Gaulle refused to cooperate on nuclear weapons with the United States, announcing a nuclear strategy of "defense in all directions" that was apparently intended to imply his willingness to use them against the Americans. He vetoed Britain's entry into the European economic partnership that later developed into the European Union, which the United States had supported. According to historian John Lewis Gaddis, de Gaulle even tried to persuade the leader of West Germany to loosen his ties with NATO, which would have seriously undermined the U.S.-led coalition and could have changed the course of the Cold War. Surely those were phone calls the United States would have been well-served by monitoring.
More U.S. spying on France may have again been useful in 1985, when New Zealand arrested two French agents caught sinking a Greenpeace ship that was set to interfere with some French nuclear tests. The United States was sucked into the incident but equivocated, perhaps believing Paris's initial claim that the French government hadn't been involved. As a result of the imbroglio, U.S. nuclear war ships are still not permitted to dock in New Zealand. Who knows how it might have gone if the U.S. had had better intelligence on its French ally?
To be sure, the U.S.-French relationship is much closer now than it was in the 1960s or even the 1980s. Still, the yo-yoing alliance is a reminder that, even if Obama and French President Hollande are buddy-buddy today, that can change quickly. The U.S.-German relationship has also had, shall we say, some historical ups and downs. There is no guarantee that just because two countries are allies today, with numerous mutual interests, this will necessarily be the case tomorrow.
Yet there's something different about heads of state. Even if a foreign leader is, in some political sense, an extension of the country they run and thus just as fair game for eavesdropping as their country's military and intelligence services, the United States does recognize that there's something sacrosanct about heads of state. That's part of the thinking behind a 1976 executive order, issued by then-President Gerald Ford, prohibiting the U.S. government from political assassinations.
Even if you're not convinced that heads of state deserve special respect from foreign spy agencies, there are real diplomatic ramifications to targeting them. Foreign militaries and intelligence agencies cannot have their pride offended by U.S. snooping because they are emotionless agencies, run by people who engage in these sorts of activities themselves and surely expect them. Merkel and Obama are also human beings; that they develop a sense of mutual trust and respect is important for their ability to cooperate on shared interests and to reach agreements. Even if spying on Merkel can help further U.S. interests, the revelation has clearly offended her personally in ways that could set those interests back. And all the negative attention is certainly hurting the United States' image in the eyes of German voters, who might become slightly less inclined to elect pro-Washington officials or support a pro-Washington agenda.
Maybe most illuminating is Merkel's response. She has demanded that U.S. tech companies be required to notify European officials every time the United States files a warrant seeking information on a Europe-based customer, which could hamper U.S. intelligence efforts significantly. She has also suggested that the United States and Germany simply sign an agreement not to spy on one another -- which would finally level the playing field between their respective intelligence agencies, long dominated by the U.S. Some analysts suspect this may be the real motive behind the outrage, as Richard McGregor and Geoff Dyer write in the Financial Times. If you can't beat your American counterparts at the intelligence game, just find a way to stop playing.
"Frau Merkel has been listened to since she was a teenager," Frederick Forsyth, a novelist and former Berlin-based correspondent told Reuters. "The only thing that amazes me about the furore is that it amazes people."
A former French foreign minister, Bernard Kouchner, also suggested the European outrage may be less about the spying crossing any moral line and more about the extent of the United States' intelligence dominance. “Let’s be honest, we eavesdrop, too," he told a French radio station. "Everyone is listening to everyone else. But we don’t have the same means as the United States, which makes us jealous.”
Even if Merkel really were unsurprised by the wiretapping and is only seizing on the revelation in a calculated attempt to undermine American intelligence dominance, it wouldn't necessarily mean that tapping foreign leaders' cellphones is ultimately in the United States' best interests, of course. But it is at least a reminder that the international system is driven more by cutthroat self-interest, and less by principles of fairness and friendliness, than its leaders often suggest.