As a former Chief of Europe Division in the CIA, I have no comment to offer concerning the Germany espionage flap, of which I know nothing, save for what I have read in the press. My intent in offering these observations is not to explain alleged CIA actions in this case. Rather, I am using this opportunity to provide a broader perspective, to relate the “rules of the game” of intelligence decision-making that applies the world over. The senior policymaker in question could be President Obama, or Chancellor Merkel, or perhaps Vladimir Putin. To each of these leaders, I would give the same advice, if asked how to handle a spy-case: there’s nothing novel here, nothing new. Let’s do what must be done and move on expeditiously, keeping our broader, shared interests in mind.

Defense establishments wage war. State Department and Foreign Ministries carry out diplomacy. Intelligence agencies conduct espionage. Certain activity sometimes blurs these roles and responsibilities, but no one should be confused as to the raison d’etre of each of these levers of state-craft. The mission of intelligence is to accomplish what diplomats and soldiers cannot. Spies steal secrets.

It has been said for good reason that intelligence is the world’s second oldest profession. It is understood in the intelligence world that all states spy on one another when presented with an irresistible opportunity to provide leaders with inside information. Policy makers turn to intelligence for one thing: a decision advantage. What leader would not want foresight and early warning of an impending terrorist attack, on foreign counterintelligence efforts to harm US interests, or to acquire crucial information on rogue state weapons of mass destruction?

Threats are unpredictable, and any state’s interests can be incompatible with another’s under certain circumstances. Thus, written no-spy agreements are inherently disingenuous. Such agreements are an explicit acknowledgment that spies are present in a country where such activity is tantamount to breaking the law. Thus, no-spy agreements favor the cynical party who is ready to abrogate its provisions when its broader interests trump cooperation. In such a case, the agreement becomes a device to exploit the naive party that has let its guard down in the false belief that any such unverifiable agreement is binding. For one should never forget that successful intelligence embraces a culture that is centered on exploiting trust and betrayal for a noble end: keeping a nation safe.

In the pursuit of this core mission, intelligence decision-making boils down to making sound judgments of whether the risks of conducting an operation justify the gains. This is true whether a state is working with other partners, or is working alone. For example, are the negatives of conducting a drone strike worth the impact of killing terrorists? Is a cyber attack on a rogue state’s nuclear program worth the resulting changes that will occur in cyber space? Is it better to ask a partner to provide information on suppliers of nuclear technology to a rogue state, or to steal the information unilaterally, if the opportunity presents itself?

In a continual quest to answer such complex questions, no serious intelligence organization can rely exclusively on cooperation with other states, even close allies, to fulfill its mission. Often, crucial information cannot be acquired through established channels for intelligence cooperation. A liaison partner might not possess the information, or it might be unwilling to share it, for institutional or legal reasons. It is not an accident that many of the greatest intelligence coups have been unilateral in nature. This tendency to go it alone was not only true during the Cold War, but was a key element of many successes of the post 9/11 period, e.g., highlights in the counter-terrorism and counter-proliferation domain.

Intelligence represents a litmus test of a state’s ability to properly gauge its self-interests. Ideally, each operational decision is weighed on the basis of a dispassionate assessment of the merits of the particular case. In practice, however, this is hard for any state to do. For one thing, most intelligence organizations have a personality-driven culture. Decisions are made in secret, and without the oversight that typifies non-intelligence government institutions.

In my experience, all policy makers like reading other people’s mail. Inside spy agencies, there is a temptation to do “art for art’s sake,” rather than forego an opportunity that might harm broader interests. It is thus incumbent on the leadership of intelligence organizations to keep the big picture of national interests in mind.

Every spy-flap reminds us that the Cold War-based espionage culture is not always a reasonable or effective basis for pursuing intelligence objectives. As a general rule, liaison cooperation simply makes more sense, in the light of current threat realities. For this reason, strange bedfellows—new partnerships between old adversaries—have emerged in responding to threats of joint concern. Old categories of “allies” and “enemies” in the intelligence world are no longer useful in pursuing liaison cooperation. More can be done to explore innovative ways to encourage restraint in conducting unilateral activity, in exchange for deeper forms of joint cooperation in core areas of shared interests. This trend will continue, to the extent states recognize that emerging threats are indeed common threats to all.

It is important to bear in mind that due to the intrinsic nature of their craft, intelligence officers cannot operate in the black and white world. They deal with the unknown, calculate probabilities, and sort variations of gray. Perhaps for this reason, establishing trust is vital, even among rogues. Intelligence officers develop strong personal relationships, they rely on their gut instincts, and they make cold-blooded assessments of self-interest. Intelligence officers assume great risks based on such intangibles. And those intangibles form the basis of deeper cooperation between intelligence agencies—not any agreements or treaties that are formed by governments.

When circumstances merit unilateral action, no one should be enamored with the idea of spying on friends, because today there is a greater sense of betrayal associated with such activity, even by the perpetrator. In some ways, the global intelligence community’s “lone wolf” tendencies have become an obstacle to developing trust-but-verify -based relationships necessary to solve transnational problems, e.g., international extremism, radicalization and terrorism, halting the spread of weapons of mass destruction; working together against organized crime, narcotics and human trafficking networks. It makes no sense for political leaders to allow spy cases to damage the broader bilateral interests between states. Much can be learned in this regard from reviewing the history of CIA-KGB spy cases; both countries have consistently strived to ensure these recurring bumps in the relationship did not do permanent damage to the bilateral interests.

In the best of all worlds, there would be no need for intelligence. But in the world we live, intelligence is a lesser evil than the threats we confront. I believe that the challenge for any free and open society is for its citizens to thoughtfully limit the power of intelligence to activity that is necessary to safeguard national security interests, and to ensure that this activity falls under appropriate oversight. In the US, it is my conviction that we have struck the right balance.