Twenty-five years ago this November, an East German Politburo member bungled the announcement of what were meant to be limited changes to travel regulations, thereby inspiring crowds to storm the border dividing East and West Berlin. The result was the iconic moment marking the point of no return in the end of the Cold War: the fall of the Berlin Wall. In the months that followed, the United States, the Soviet Union, and West Germany engaged in fateful negotiations over the withdrawal of Soviet troops and the reunification of Germany. Although these talks eventually resulted in German reunification on October 3, 1990, they also gave rise to a later, bitter dispute between Russia and the West. What, exactly, had been agreed about the future of NATO? Had the United States formally promised the Soviet Union that the alliance would not expand eastward as part of the deal?

Even more than two decades later, the dispute refuses to go away. Russian diplomats regularly assert that Washington made just such a promise in exchange for the Soviet troop withdrawal from East Germany -- and then betrayed that promise as NATO added 12 eastern European countries in three subsequent rounds of enlargement. Writing in this magazine earlier this year, the Russian foreign policy thinker Alexander Lukin accused successive U.S. presidents of “forgetting the promises made by Western leaders to Mikhail Gorbachev after the unification of Germany -- most notably that they would not expand NATO eastward.” Indeed, Russian President Vladimir Putin’s aggressive actions in Georgia in 2008 and Ukraine in 2014 were fueled in part by his ongoing resentment about what he sees as the West’s broken pact over NATO expansion. But U.S. policymakers and analysts insist that such a promise never existed. In a 2009 Washington Quarterly article, for example, the scholar Mark Kramer assured readers not only that Russian claims were a complete “myth” but also that “the issue never came up during the negotiations on German reunification.”

Now that increasing numbers of formerly secret documents from 1989 and 1990 have made their way into the public domain, historians can shed new light on this controversy. The evidence demonstrates that contrary to the conventional wisdom in Washington, the issue of NATO’s future in not only East Germany but also eastern Europe arose soon after the Berlin Wall opened, as early as February 1990. U.S. officials, working closely with West German leaders, hinted to Moscow during negotiations that month that the alliance might not expand, not even to the eastern half of a soon-to-be-reunited Germany.

Documents also show that the United States, with the help of West Germany, soon pressured Gorbachev into allowing Germany to reunify, without making any kind of written promise about the alliance’s future plans. Put simply, there was never a formal deal, as Russia alleges -- but U.S. and West German officials briefly implied that such a deal might be on the table, and in return they received a “green light” to commence the process of German reunification. The dispute over this sequence of events has distorted relations between Washington and Moscow ever since.

GETTING THE GREEN LIGHT

Western leaders quickly realized that the fall of the Berlin Wall had brought seemingly long-settled issues of European security once again into play. By the beginning of 1990, the topic of NATO’s future role was coming up frequently during confidential conversations among U.S. President George H. W. Bush; James Baker, the U.S. secretary of state; Helmut Kohl, the West German chancellor; Hans-Dietrich Genscher, the West German foreign minister; and Douglas Hurd, the British foreign minister.

According to documents from the West German foreign ministry, for example, Genscher told Hurd on February 6 that Gorbachev would want to rule out the prospect of NATO’s future expansion not only to East Germany but also to eastern Europe. Genscher suggested that the alliance should issue a public statement saying that “NATO does not intend to expand its territory to the East.” “Such a statement must refer not just to [East Germany], but rather be of a general nature,” he added. “For example, the Soviet Union needs the security of knowing that Hungary, if it has a change of government, will not become part of the Western Alliance.” Genscher urged that NATO discuss the matter immediately, and Hurd agreed.

Three days later, in Moscow, Baker talked NATO with Gorbachev directly. During their meeting, Baker took handwritten notes of his own remarks, adding stars next to the key words: “End result: Unified Ger. anchored in a ´changed (polit.) NATO -- ´whose juris. would not move ´eastward!” Baker’s notes appear to be the only place such an assurance was written down on February 9, and they raise an interesting question. If Baker’s “end result” was that the jurisdiction of NATO’s collective-defense provision would not move eastward, did that mean it would not move into the territory of former East Germany after reunification?

In answering that question, it is fortunate for posterity’s sake that Genscher and Kohl were just about to visit Moscow themselves. Baker left behind with the West German ambassador in Moscow a secret letter for Kohl that has been preserved in the German archives. In it, Baker explained that he had put the crucial statement to Gorbachev in the form of a question: “Would you prefer to see a unified Germany outside of NATO, independent and with no U.S. forces,” he asked, presumably framing the option of an untethered Germany in a way that Gorbachev would find unattractive, “or would you prefer a unified Germany to be tied to NATO, with assurances that NATO’s jurisdiction would not shift one inch eastward from its present position?”

Baker’s phrasing of the second, more attractive option meant that NATO’s jurisdiction would not even extend to East Germany, since NATO’s “present position” in February 1990 remained exactly where it had been throughout the Cold War: with its eastern edge on the line still dividing the two Germanies. In other words, a united Germany would be, de facto, half in and half out of the alliance. According to Baker, Gorbachev responded, “Certainly any extension of the zone of NATO would be unacceptable.” In Baker’s view, Gorbachev’s reaction indicated that “NATO in its current zone might be acceptable.”

After receiving their own report on what had happened in Moscow, however, staff members on the National Security Council back in Washington felt that such a solution would be unworkable as a practical matter. How could NATO’s jurisdiction apply to only half of a country? Such an outcome was neither desirable nor, they suspected, necessary. As a result, the National Security Council put together a letter to Kohl under Bush’s name. It arrived just before Kohl departed for his own trip to Moscow.

Instead of implying that NATO would not move eastward, as Baker had done, this letter proposed a “special military status for what is now the territory of [East Germany].” Although the letter did not define exactly what the special status would entail, the implication was clear: all of Germany would be in the alliance, but to make it easier for Moscow to accept this development, some kind of face-saving regulations would apply to its eastern region (restrictions on the activities of certain kinds of NATO troops, as it turned out).

Kohl thus found himself in a complicated position as he prepared to meet with Gorbachev on February 10, 1990. He had received two letters, one on either end of his flight from West Germany to the Soviet Union, the first from Bush and the second from Baker, and the two contained different wording on the same issue. Bush’s letter suggested that NATO’s border would begin moving eastward; Baker’s suggested that it would not.

According to records from Kohl’s office, the chancellor chose to echo Baker, not Bush, since Baker’s softer line was more likely to produce the results that Kohl wanted: permission from Moscow to start reunifying Germany. Kohl thus assured Gorbachev that “naturally NATO could not expand its territory to the current territory of [East Germany].” In parallel talks, Genscher delivered the same message to his Soviet counterpart, Eduard Shevardnadze, saying, “for us, it stands firm: NATO will not expand itself to the East.”

As with Baker’s meeting with Gorbachev, no written agreement emerged. After hearing these repeated assurances, Gorbachev gave West Germany what Kohl later called “the green light” to begin creating an economic and monetary union between East and West Germany -- the first step of reunification. Kohl held a press conference immediately to lock in this gain. As he recalled in his memoirs, he was so overjoyed that he couldn’t sleep that night, and so instead went for a long, cold walk through Red Square.

BRIBING THE SOVIETS OUT

But Kohl’s phrasing would quickly become heresy among the key Western decision-makers. Once Baker got back to Washington, in mid-February 1990, he fell in line with the National Security Council’s view and adopted its position. From then on, members of Bush’s foreign policy team exercised strict message discipline, making no further remarks about NATO holding at the 1989 line.

Kohl, too, brought his rhetoric in line with Bush’s, as both U.S. and West German transcripts from the two leaders’ February 24–25 summit at Camp David show. Bush made his feelings about compromising with Moscow clear to Kohl: “To hell with that!” he said. “We prevailed, they didn’t. We can’t let the Soviets clutch victory from the jaws of defeat.” Kohl argued that he and Bush would have to find a way to placate Gorbachev, predicting, “It will come down in the end to a question of cash.” Bush pointedly noted that West Germany had “deep pockets.” A straightforward strategy thus arose: as Robert Gates, then U.S. deputy national security adviser, later explained it, the goal was to “bribe the Soviets out.” And West Germany would pay the bribe.

In April, Bush spelled out this thinking in a confidential telegram to French President François Mitterrand. U.S. officials worried that the Kremlin might try to outmaneuver them by allying with the United Kingdom or France, both of which were also still occupying Berlin and, given their past encounters with a hostile Germany, potentially had reason to share the Soviets’ unease about reunification. So Bush emphasized his top priorities to Mitterrand: that a united Germany enjoy full membership in NATO, that allied forces remain in a united Germany even after Soviet troops withdraw, and that NATO continue to deploy both nuclear and conventional weapons in the region. He warned Mitterrand that no other organization could “replace NATO as the guarantor of Western security and stability.” He continued: “Indeed, it is difficult to visualize how a European collective security arrangement including Eastern Europe, and perhaps even the Soviet Union, would have the capability to deter threats to Western Europe.”

Bush was making it clear to Mitterrand that the dominant security organization in a post–Cold War Europe had to remain NATO -- and not any kind of pan-European alliance. As it happened, the next month, Gorbachev proposed just such a pan-European arrangement, one in which a united Germany would join both NATO and the Warsaw Pact, thus creating one massive security institution. Gorbachev even raised the idea of having the Soviet Union join NATO. “You say that NATO is not directed against us, that it is simply a security structure that is adapting to new realities,” Gorbachev told Baker in May, according to Soviet records. “Therefore, we propose to join NATO.” Baker refused to consider such a notion, replying dismissively, “Pan-European security is a dream.”

Throughout 1990, U.S. and West German diplomats successfully countered such proposals, partly by citing Germany’s right to determine its alliance partners itself. As they did so, it became clear that Bush and Kohl had guessed correctly: Gorbachev would, in fact, eventually bow to Western preferences, as long as he was compensated. Put bluntly, he needed the cash. In May 1990, Jack Matlock, the U.S. ambassador to Moscow, reported that Gorbachev was starting to look “less like a man in control and more [like] an embattled leader.” The “signs of crisis,” he wrote in a cable from Moscow, “are legion: Sharply rising crime rates, proliferating anti-regime demonstrations, burgeoning separatist movements, deteriorating economic performance . . . and a slow, uncertain transfer of power from party to state and from the center to the periphery.”

Moscow would have a hard time addressing these domestic problems without the help of foreign aid and credit, which meant that it might be willing to compromise. The question was whether West Germany could provide such assistance in a manner that would allow Gorbachev to avoid looking as though he was being bribed into accepting a reunified Germany in NATO with no meaningful restrictions on the alliance’s movement eastward.

Kohl accomplished this difficult task in two bursts: first, in a bilateral meeting with Gorbachev in July 1990, and then, in a set of emotional follow-up phone calls in September 1990. Gorbachev ultimately gave his assent to a united Germany in NATO in exchange for face-saving measures, such as a four-year grace period for removing Soviet troops and some restrictions on both NATO troops and nuclear weapons on former East German territory. He also received 12 billion deutsch marks to construct housing for the withdrawing Soviet troops and another three billion in interest-free credit. What he did not receive were any formal guarantees against NATO expansion.

In August 1990, Saddam Hussein’s invasion of Kuwait immediately pushed Europe down the White House’s list of foreign policy priorities. Then, after Bush lost the 1992 presidential election to Bill Clinton, Bush’s staff members had to vacate their offices earlier than they had expected. They appear to have communicated little with the incoming Clinton team. As a result, Clinton’s staffers began their tenure with limited or no knowledge of what Washington and Moscow had discussed regarding NATO.

THE SEEDS OF A FUTURE PROBLEM

Contrary to the view of many on the U.S. side, then, the question of NATO expansion arose early and entailed discussions of expansion not only to East Germany but also to eastern Europe. But contrary to Russian allegations, Gorbachev never got the West to promise that it would freeze NATO’s borders. Rather, Bush’s senior advisers had a spell of internal disagreement in early February 1990, which they displayed to Gorbachev. By the time of the Camp David summit, however, all members of Bush’s team, along with Kohl, had united behind an offer in which Gorbachev would receive financial assistance from West Germany -- and little else -- in exchange for allowing Germany to reunify and for allowing a united Germany to be part of NATO.

In the short run, the result was a win for the United States. U.S. officials and their West German counterparts had expertly outmaneuvered Gorbachev, extending NATO to East Germany and avoiding promises about the future of the alliance. One White House staffer under Bush, Robert Hutchings, ranked a dozen possible outcomes, from the “most congenial” (no restrictions at all on NATO as it moved into former East Germany) to the “most inimical” (a united Germany completely outside of NATO). In the end, the United States achieved an outcome somewhere between the best and the second best on the list. Rarely does one country win so much in an international negotiation.

But as Baker presciently wrote in his memoirs of his tenure as secretary of state, “Almost every achievement contains within its success the seeds of a future problem.” By design, Russia was left on the periphery of a post–Cold War Europe. A young KGB officer serving in East Germany in 1989 offered his own recollection of the era in an interview a decade later, in which he remembered returning to Moscow full of bitterness at how “the Soviet Union had lost its position in Europe.” His name was Vladimir Putin, and he would one day have the power to act on that bitterness.