The Eastern Front expansion of NATO served as the impetus for Russian incursions into Ukraine, which were precipitated by breaches of the agreements established to end the Iron Curtain.

Our opposition to the eastward expansion of NATO is grounded in the historical context of negotiations between the Soviet Union and Russia preceding and following the Iron Curtain collapse.  Furthermore, the Russians considered us to have violated our agreement. This is not a point of contention or complaint on their part; rather, it is supported by well-documented information that was utilized and composed throughout the negotiations with the USSR prior to and even after its fall.  Further expansion should cease, and Ukraine should be relegated to a neutral border state devoid of Soviet or American military installations. This is how the majority of the countries comprising the Eastern Bloc should have been treated following Germany's reunification.

The National Security Agency's declassified U.S., Soviet, German, British, and French documents show that Secretary of State James Baker's February 9, 1990 “not one inch eastward” NATO expansion assurance to Soviet leader Mikhail Gorbachev was part of a cascade of Western security assurances to Gorbachev and other Soviet officials during German unification in 1990 and 1991.

From early 1990 to 1991, multiple national leaders considered and rejected Central and Eastern European membership in NATO, NATO discussions in the context of German unification negotiations in 1990 were not limited to East German territory, and Soviet and Russian complaints about being misled about NATO expansion were based on contemporaneous memcons and telcons.

The documents support former CIA Director Robert Gates's criticism of “pressing ahead with expansion of NATO eastward [in the 1990s], when Gorbachev and others were led to believe that wouldn't happen.”

Bush told Gorbachev at the December 1989 Malta summit that the U.S. would not use the Eastern European revolutions to harm Soviet interests (“I have not jumped up and down on the Berlin Wall”). Bush, Gorbachev, and Kohl did not expect East Germany to collapse or German unification to happen so quickly.

In Tutzing, Bavaria, West German Foreign Minister Hans-Dietrich Genscher opened the bidding with a major public speech on German unification, delivering the first Western NATO assurances. U.S. Embassy in Bonn informed Washington that Genscher stated “that the changes in Eastern Europe and the German unification process must not lead to a ‘impairment of Soviet security interests.’” NATO should avoid "expansion of its territory towards the east, i.e. moving it closer to the Soviet borders." Genscher proposed excluding East Germany from NATO military structures, as noted in the Bonn cable.On September 12, 1990, four foreign ministers signed the final German unification treaty, granting the GDR special status. In 1990 and 1991, the Soviets and their top Western allies (Genscher, Kohl, Baker, Gates, Bush, Mitterrand, Thatcher, Major, Woerner, and others) exchanged memoranda promising to protect Soviet security interests and include the USSR in new European security structures. The issues were related but distinct. Sometimes later analysis confused the two and claimed the discussion did not involve all of Europe. Documents below prove it did.

The “Tutzing formula” sparked a flurry of important diplomatic discussions over the next 10 days in 1990, culminating in Kohl and Gorbachev's February 10, 1990, meeting in Moscow, where Kohl won Soviet assent to German unification in NATO, as long as NATO did not expand eastward. The Soviets needed more time to work with domestic opinion and West German financial aid before signing the deal in September 1990.

Discussions about NATO expansion, Central and East European countries, and Soviet unification preceded Kohl's assurance. Genscher told British Foreign Minister Douglas Hurd on February 6, 1990, “The Russians must have some assurance that if, for example, the Polish Government left the Warsaw Pact one day, they would not join NATO the next.”

Baker met with Genscher before meeting the Soviets and repeated Genscher's formulation in his February 9, 1990, meeting with Foreign Minister Eduard Shevardnadze and, more importantly, Gorbachev.

Baker three times told Gorbachev “not one inch eastward” on February 9, 1990. Gorbachev declared “NATO expansion is unacceptable.” Baker told Gorbachev that “neither the President nor I intend to extract any unilateral advantages from the processes that are taking place,” and that the Americans understood that “not only for the Soviet Union but for other European countries as well it is important to have guarantees that if the United States keeps its presence in Germany within the

Baker used similar language to write to Helmut Kohl, who would meet the Soviet leader the next day. Baker wrote, “I asked Gorbachev the following question. Would you rather see a united Germany outside NATO, independent, and without U.S. forces, or tied to NATO with guarantees that NATO's jurisdiction would not shift eastward? Baker said the Soviet leadership was considering all options but would not extend NATO's zone. Baker also suggested NATO's zone was fine.

After being briefed by the US secretary of state, the West German chancellor told Gorbachev on February 10, 1990: “We believe that NATO should not expand the sphere of its activity.” Kohl was thrilled when Gorbachev agreed to unify Germany and let Germany choose NATO under the Helsinki formula. Kohl wrote about walking all night in Moscow knowing the cost in his memoirs.

All Western foreign ministers backed Genscher, Kohl, and Baker. British foreign minister Douglas Hurd followed on April 11, 1990. Kohl surprised everyone by winning the March 18 elections, and East Germans overwhelmingly supported the deutschmark and rapid unification. Kohl correctly predicted that the GDR's collapse would open all possibilities, that he had to run to the head of the train, that he needed U.S. support, and that unification could happen faster than expected (first told Bush on December 3, 1989). Security assurances continued as monetary union began in July. Hurd told Gorbachev in Moscow on April 11, 1990, that Britain “recognized the importance of doing nothing to prejudice Soviet interests and dignity.”

Baker wrote to President Bush that he used your speech and our recognition of the need to adapt NATO, politically and militarily, and to develop CSCE to reassure Shevardnadze that the process would not produce winners and losers. It would establish an inclusive, legitimate European structure.

Baker repeated his "nine points" to Gorbachev in Moscow on May 18, 1990, including NATO transformation, European structure strengthening, Germany non-nuclear status, and Soviet security interests. Baker began, “Before speaking about the German issue, I wanted to emphasize that our policies do not aim to separate Eastern Europe from the Soviet Union. Once, that policy existed. Today, we want to build a stable Europe with you.”

On May 25, 1990, Francois Mitterrand told Gorbachev in Moscow that the West must “create security conditions for you, as well as European security as a whole” and “personally in favor of gradually dismantling the military blocs.” Mitterrand immediately wrote Bush a “cher George” letter.

Bush assured Gorbachev at the May 31, 1990 Washington summit that NATO Germany would never target the USSR: “Believe me, we are not pushing Germany towards unification, and it is not us who determines the pace of this process. Naturally, we don't want to hurt the USSR. Considering the two German states' economic ties, we support NATO-German unification without ignoring the CSCE. We think this model suits Soviet interests.

In her June 8, 1990 London meeting with Gorbachev, the “Iron Lady” contributed after the Washington summit. Thatcher predicted American support for Gorbachev at the early July NATO conference by describing NATO's political, less militarily threatening transformation. She stressed Soviet security to Gorbachev.

The NATO London Declaration on July 5, 1990, boosted Moscow deliberations and gave Gorbachev ammunition to fight his hardliners at the Party Congress, according to most accounts. Shevardnadze's aides were either given an advance copy or told to take the wire service copy and produce a Soviet positive assessment before the military or hardliners could call it propaganda.

Kohl told Gorbachev in Moscow on July 15, 1990, as they completed German unification: “We know what awaits NATO in the future, and I think you are now in the know as well,” referring to the NATO London Declaration.

Bush called Gorbachev on July 17 to support the London Declaration and Kohl-Gorbachev talks. Bush said: "We tried to address your concerns expressed to me and others in the following ways: by our joint declaration on non-aggression; by our invitation to you to join NATO; by our agreement to open NATO to regular diplomatic contact with your government and those of Eastern European countries; and by our offer of assurances on the future size of the armed forces of a united Germany." We revamped our conventional and nuclear military strategies. To join the new Europe, we proposed a stronger, more institutionalized CSCE for the USSR.

The documents show that Gorbachev agreed to German unification in NATO after this cascade of assurances and on the basis of his analysis that the Soviet Union's future depended on its integration into Europe, where Germany would be the key player. His and most of his allies believed that the common European home was still possible and would evolve with NATO's transformation to create a more inclusive and integrated European space, taking Soviet security interests into account in the post-Cold War settlement. The Cold War and Great Patriotic War ended with the German alliance.

U.S. officials debated NATO-Eastern Europe relations. Though opinions varied, the Defense Department advised leaving “the door ajar” for East European NATO membership on October 25, 1990. The State Department worried NATO expansion would create “an anti-Soviet coalition” that could reverse Soviet progress. The Bush administration believed it. It reached the Soviets.

The British ambassador to Moscow's diary states that Prime Minister John Major told Gorbachev, “We are not talking about the strengthening of NATO.” Major replied, “Nothing of the sort will happen.” Soviet defense minister Marshal Dmitri Yazov asked Major about East European leaders' NATO membership interest.

In Brussels, Russian Supreme Soviet deputies met NATO secretary-general Manfred Woerner in July 1991. Woerner warned against isolating the USSR from Europe, saying the NATO Council and he oppose NATO expansion (13 of 16 NATO members agree).

Gorbachev left the USSR confident NATO was not a security threat. Russians Boris Yeltsin and Gennady Burbulis and former Soviet republic party bosses, especially Ukraine, dissolved the USSR in December 1991. Long after the Cold War. The August 1, 1991 Bush “Chicken Kiev” speech documented American efforts to save the USSR. When these disputes resurfaced and Boris Yeltsin received more assurances, NATO expansion was years away.