The analysis relies on extensive sources, including over 100 interviews and primary documents and records of contacts between the White House and the Kremlin.

Among the turns, she counts Bush's refusal to Baker to give Russia an assurance about non-enlargement, the failure of the Partnership for Peace and the NATO summit in Washington in 1999.

Sarotte describes how Helmut Kohl and George H. W. Bush pushed ahead with NATO expansion into East Germany in order to secure the achievements of the Cold War, while Moscow was struggling for power.

With his ten-point plan, Helmut Kohl had preempted Russia's demand that a united Germany must "withdraw from NATO" so that the USSR could agree to reunification.

In an article for the Financial Times in 2023, she highlighted this element once again:What is crucial for any accurate account, however, is the knowledge that this discussion was speculative and highly contingent – and that Baker's boss, US President George H. W. Bush, made it clear at the end of February that he did not consider a limitation of NATO's future desirable or necessary.

In obedience, Baker wrote confidentially to his German colleagues in the same month that discussions about NATO's area of responsibility "should be avoided in the future.

US Secretary of Defense William Perry and General John Shalikashvili had therefore proposed the Partnership for Peace, which Yeltsin was enthusiastic about.

According to Sarotte, skilled bureaucratic fighters such as Antony Lake and Richard Holbrooke immediately launched a full-scale attack on this proposal, which was supported by Madeleine Albright.

When Yevgeny Primakov became foreign minister in 1996 and Yeltsin's health was weakening, Sarotte said, the Russian opposition to NATO gained new impetus.

For Russia, NATO's military action in Kosovo, which was not approved by the UN, came as a shock, which Yeltsin's critics commented on with the words: "Today Belgrade, tomorrow Moscow."

Begovic also finds the US government's adherence to decisions once made remarkable and explains this with credibility and reputation being of the utmost importance making it difficult to admit mistakes.

For the other, the American side, it was a matter of "business as usual" – the preservation of what the political elite considered to be the strategic interests of the United States vis-à-vis the other side.The way in which the US helped Russia obtain loans from the IMF "against the rules", similar to what it later did with Ukraine, ruined international institutions and their credibility, according to Begovic.

Dembinski critically notes that Sarotte may be underestimating the importance of the NATO-Russia Founding Act for the European security architecture.

In his opinion, the book's overwhelming evidence suggests that George H. W. Bush and Bill Clinton slowed down NATO expansion in order to try to stabilize the government of Russian President Boris Yeltsin in the short term, waiting as long as he still seemed viable.

"It was only when Yeltsin's fall was imminent and a hardening of East-West relations seemed inevitable that the United States began to expand the alliance."

He said the book had a "great narrative and analytical flair, admirable objectivity", he praised the details and said it was a riveting account of NATO enlargement.

[8] Bradley Reynolds' review (2021) emphasizes Sarotte's understanding that, due to the "ongoing negotiation aspect of NATO's role" in the 1990s, the statement not an inch was more an expression of a multifaceted, fluctuating process of "common complicity" than a singular promise between Baker and Gorbachev in 1990.

The collapse of the Soviet Union and the emerging threat of nuclear proliferation in the New Independent States had prompted NATO to reconsider enlargement beyond a reunified Germany.

However, he emphasizes that the author did not see her work as a "final word" but as a starting point for further research and agrees with Marc Trachtenberg's judgment that historical scholarship cannot judge the political value and worthlessness of events.

"[11] In his review of December 1, 2022, Marcin Waldoch (Uniwersytet Kazimierza Wielkiego w Bydgoszcz) criticises Sarotte's implicit view that NATO's eastward expansion had been harmful to the world order.

Waldoch does not see NATO membership for countries like Poland as a geopolitical decision by the West, but as an existential need to ensure their own sovereignty and security after decades of Soviet dominance.

He notes that much of the information comes from journalistic sources such as the New York Times or the Washington Post, which he believes may limit the depth and objectivity of the analysis.

Nevertheless, he acknowledges the quality of research and the analytical strength of Sarotte's work but sees the need to focus more strongly on the perspective of the Eastern European countries concerned.

Joshua Jaffa judged in The New Yorker in January 2022, a month before the start of the war, that Sarotte's new findings both fill in and complicate the established narratives on both sides.

Sarotte told him that she wanted to write a "non-triumphalist history" of the end of the Cold War, the opposite of the version "that most of us know: a story of victory, freedom and opportunity."

"Sarotte would not say that the West had taken advantage of Russia, but the Western powers would have done well to heed an aphorism by Winston Churchill: "In victory: magnanimity".

James Baker, the US Secretary of State at the time, had actually sounded out the possibility in 1990 in a conversation with Mikhail Gorbachev whether Moscow would agree to German unity in exchange for the promise that NATO would not expand eastwards.

In accordance with Bush's instructions, Baker then let the issue rest, while Hans-Dietrich Genscher did not and was reprimanded for it in a letter from Chancellor Helmut Kohl.