Breathless coverage of the revelations that the National Security Agency (NSA) has been tracking allied foreign leaders aside, spying on allies -- even friendly ones -- is nothing new in international politics. In the mid-sixteenth century, the pious King Philip II of Spain and the pope kept tabs on each other as they prepared for the sailing of the Spanish Armada against Britain. The reason? The pope thought the king indecisive, and the king believed that the pope was hedging his bets.

Centuries later, in early 1917, the British government wanted the United States, then neutral, to enter World War I on its side. According to Keith Jeffery, the official historian of MI6, London’s intelligence service, the British used a “whole range” of overt and clandestine methods to gather intelligence and run influence operations. For example, thanks to its secret surveillance of a U.S. transatlantic cable, MI6 learned of a German plot to win Mexico’s allegiance by promising the country a chunk of U.S. territory. Masking its source, MI6 delivered the alarming news to U.S. President Woodrow Wilson and thus nudged the United States toward a declaration of war. 

Signal intercepts were not the United Kingdom’s only source of intelligence on its hoped-for ally: Sir William Wiseman, a British intelligence operative, penetrated the White House by earning the trust of Wilson and his closest adviser, Colonel Edward House. While also running illegal covert operations on U.S. soil, Wiseman gathered intelligence on Washington’s opinions about the conduct of the war, its preferences for how some postwar territorial issues would be resolved, and its strategy for the Paris Peace Conference.

The United States returned the favor by collecting the communications of friendly powers during the peace negotiations. Even as Wilson publicly espoused open diplomacy, his closest advisers had hired the cryptologist Herbert Yardley to run a signal and cipher unit that gathered intelligence on the other delegations. Yardley provided a similar service at the Washington Naval Conference, during which, thanks to his work, the United States was able to win major limitations on the presence of foreign navies in the Pacific. Shocked to learn of Yardley’s activities, U.S. Secretary of State Henry Stimson shut down his “Black Chamber” in 1929, declaring that “gentlemen do not read each other’s mail.” But Stimson changed his mind soon thereafter, advocating the creation of a successor, the NSA, after World War II.

Israelis hold placards depicting Jonathan Pollard during a protest calling for his release from a U.S. prison, outside U.S. Secretary of State John Kerry's hotel in Jerusalem January 2, 2014.
Ammar Awad / Reuters
Friends don’t just tap friends’ phones and read their mail. In one particularly notorious case, the Israeli government bought sensitive intelligence from a U.S. analyst, Jonathan Pollard, who received a life sentence for espionage in 1987. Despite appeals from the highest levels in Tel Aviv, Pollard remains in a North Carolina prison. Meanwhile, in 2003, the United States was caught spying in Italy because it wanted to render a terrorist out of the country. The Italians were not amused and, in 2009, convicted the American station chief and 22 others. To catch the operatives, Italian law enforcement had monitored the cell phones of a friendly intelligence service. 

That everyone does it is, of course, no excuse for intelligence run amok, as insiders argue was the case in the Pollard espionage. The Israeli government recruited and rewarded Pollard for collecting intelligence on Arab militaries, but it apparently accepted his intelligence on U.S. sources and methods as well. The overreach was hardly in Israel’s interests given the risks to its larger relationship with the United States.  

There are, however, plenty of good reasons for allies to spy on each other: to protect interests that an ally disregards, to guard against double-dealing or betrayal, to protect against allied vulnerabilities, to guard against surprise stemming from diverging interests, and to protect against a good “friend” simply getting things wrong. Wiseman’s role in the run-up to the United States joining World War I, a role that was reprised by William Stephenson in the lead-up to World War II, could be put in that last category. Although U.S. interests lay with the United Kingdom in both cases, U.S. entry into the wars was uncertain. London’s mission was to learn American thinking and nudge Washington along.

One of these legitimate categories concerns the disregard of an ally’s interests. For example, U.S. soldiers sometimes go to war against states equipped with highly advanced weapons sold to them by third parties, including allies. Understanding how to defend against these weapons may require information on how they work. Although it is unconscionable for governments to gather such proprietary information from foreign firms for competitive advantage, doing so to protect soldiers’ lives and win wars may be necessary if an allied government refuses to hand the data over or make its industry divulge it. Allies deny such intelligence to each other because, although politically friendly, they are still economic competitors; their counterintelligence services are, as a result, often at war with each other. 

Guarding against betrayal, whether deliberate or accidental, is also unexceptionable. None of the United States’ partners in World War II fully trusted the others, particularly as the United States developed its nuclear weapons. Even in the context of the British-American special relationship, which rapidly grew after World War II, both governments were watching each other closely -- and for good reason. The United States’ Venona project, which entailed the decryption of Soviet message traffic during the war, revealed that sensitive documents were being sent to Moscow from the British embassy in Washington. Before the governments could react, two British double-agents, Donald MacLean and Guy Burgess, had fled to the Soviet Union. Thus, Washington learned that its ally had failed to detect Soviet moles that were compromising U.S. security. A similar problem arose for the United States in the 1970s, when its NATO partner, West Germany, discovered that the East German intelligence service had planted a communist spy, Günter Guillaume, in West German Chancellor Willy Brandt’s inner circle. When the infiltration was revealed, Brandt resigned, but the damage was NATO-wide. Among the secrets Guillaume apparently provided his government were letters to Brandt from U.S. President Richard Nixon concerning NATO nuclear strategy.

At times, it is the ally’s very decision-making process that is the problem. It is well understood that poor U.S. intelligence on weapons of mass destruction prior to the Iraq war tainted Washington’s decision-making. It is not surprising that U.S. allies facing a “war of choice” and questionable U.S. information would monitor the United States to determine what American policymakers really believed. That is exactly what they did, with mixed results. In the famous Downing Street memo, the British head of MI6 reported that "[George W.] Bush wanted to remove Saddam Hussein, through military action, justified by the conjunction of terrorism and WMD. But the intelligence and facts were being fixed around the policy.” Those allies who did not second-guess American reasoning paid the price.

In international politics, friendship is a misnomer. Relations among states cannot -- or at least should not -- entail true trust. States exist to keep their respective nations safe, and even allies can put each other at risk. In a world full of complex interests, countries cooperate where they can but seek information where they must, weighing the risks to alliances, international institutions, and strategies as they go. Although there are reasons why U.S. spying on Germany or other European powers may be necessary, there are also good reasons for political leaders to ensure that these missions be performed with great discretion and only when regular diplomatic or intelligence liaison channels do not suffice. In turn, allied governments, which know their own intelligence histories well, would do best to respond to disclosures with temperance instead of heated rhetoric. After all, U.S. intelligence helped prevent the Cold War from going hot and contributed to Germany becoming whole again. That the United States spent and risked so much for Europe suggests not only that the two are good allies, but that what the German chancellor is thinking is at the very heart of what the United States needs to know to remain a good friend.

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  • JENNIFER SIMS is Senior Fellow for National Security at the Chicago Council on Global Affairs and a Visiting Professor in the Security Studies Program at Georgetown University.
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