The first decades after World War II were characterized by the bipolar world order between East and West, which had an impact on almost every aspect of international relations. The world got used to it and respected the other side’s red lines in the interest of avoiding a new major war, possibly fought also with nuclear weapons. And, especially since the late 1960s, the West sought to ensure security and stability through dialogue, cooperation, and the establishment of a sustainable military balance through arms control agreements. This was done under the impression that the confrontation between the “systems” was insurmountable. Dramatically increased armament efforts by the United States and NATO, growing economic weaknesses and overstretching on the part of the Soviet Union and the Warsaw Pact, and “softening,” reformist misjudgments, and diplomatic concessions on the part of the Soviet leadership under Mikhail Gorbachev finally led to the bloc confrontation being overcome. The Cold War came to an end at the beginning of the 1990s. Western values, which had already been agreed on in the Conference for Security and Cooperation in Europe (CSCE) process (see: Helsinki Final Act of 1975) and originally written off by the Warsaw Pact as purely rhetorical concessions of no relevance, prevailed.

The new situation in the states of the former Soviet Union and the Warsaw Pact, characterized above all by chaotic conditions and disintegration, required stabilization measures to be carried out with finesse and sensitivity. This initially meant hedging the risks due to the traumatic disruption and political dissolution in Eastern and Central Eastern Europe. This was beginning in the early 1990s achieved through the negotiation and implementation of stabilizing arms control agreements such as the Treaty on Conventional Armed Forces in Europe; the Open Skies Treaty; the START I and II treaties to reduce strategic means of delivery for nuclear weapons; the pledges codified in the Presidential Nuclear Initiatives to reduce tactical nuclear weapons; and the expansion of confidence- and security-building measures (Vienna Documents). Ultimately, these agreements—together with the Treaty on Intermediate-Range Nuclear Forces (INF) concluded back in 1987—formed the basis for creating mutual trust and a smooth transition to a new phase in which Germany, too, saw the possibility of dramatically reducing its armed forces even unilaterally, without affecting its security.

In addition, the “Charter of Paris for a New Europe,” agreed upon as early as 1990 within the framework of the CSCE, marked the joint commitment to overcoming the division of Europe and to a new peace order based on Western values such as democracy, human rights, and the rule of law. The system of collective security that was created in this way—in which all the states of the CSCE (later the Organization for Security and Cooperation in Europe or OSCE) were to ensure peace and security among themselves jointly, equally, and inclusively—is still the key reference point whenever the security order that was destroyed by Russia’s war of aggression against Ukraine is referred to in official speeches.

However, the CSCE/OSCE as a collective security system did not have a high political status even in the 1990s; it was increasingly marginalized after the turn of the millennium. As an outward-looking defense alliance essentially directed against Russia, NATO remained the dominant security organization for Europe. Immediately after the end of the Cold War, former Warsaw Pact states as well as some of the Soviet Union’s successor states sought to join NATO in order to protect themselves from Russia. Due to historical experience, the aversion to Russia was deep-rooted.

NATO responded to this interest with an expansion process that was initially carried out with great consideration for Russia’s sensitivities. This was reflected in the 2+4 Treaty and in the NATO-Russia Founding Act. In addition to an explicit security partnership with Russia, this also involved concrete unilateral military restraint commitments (e.g., NATO refraining from stationing armed forces and nuclear weapons on the territory of the former German Democratic Republic and refraining from stationing “substantial combat forces” as well as nuclear weapons in the new NATO member states).

Boris Yeltsin had reservations about NATO expansion. However, the East-West antagonism intensified markedly when Presidents Vladimir Putin and George W. Bush took office in 2000 and 2001. Bush saw a unipolar moment in international relations; he believed that the United States was capable and qualified to dominate international relations. This went hand in hand with an arrogant disregard for the considerations often invoked by the West, especially during the Cold War: Instead of relying on military balance, Bush now proclaimed that the superiority (“full spectrum dominance”) of the American armed forces would ensure security. He also began systematically and without much ado casting off commitments that he perceived as restricting American freedom of action, especially in the area of arms control. In 2002, for example, he withdrew from the Treaty on the Limitation of Anti-Ballistic Missile Defense Systems (ABM Treaty) concluded with the Soviet Union more than thirty years earlier, which formed the basis for strategic stability between the two great powers. The next phases of NATO expansion were now also being implemented without unilateral military restraint commitments that would cushion Russia. The United States also pushed for Ukraine and Georgia to rapidly join NATO, despite staunch Russian resistance. Germany and France opposed this due to the belief that such a move would provoke Russia and negatively impact European security. They reached a compromise formulation at the NATO summit in 2008 that included the general prospect of NATO membership for both countries but blocked the beginning of the accession process.

Putin felt challenged by the new American policy under Bush. He was ultimately concerned with the recognition and preservation of Russia’s status as a great power on an equal footing with the United States, which the latter actually rejected; they only saw Russia as a “regional power,” as even President Barack Obama still put it. Putin took a clear counter-position to the United States and complained bitterly about the disregard for Russian interests at the Munich Security Conference in 2007. After the chaotic Yeltsin years, however, he saw Russia as hardly able to assert its interests in the short term, either economically or militarily. However, he drew “red lines” for NATO expansion through military interventions in Georgia in 2008 and in Ukraine in 2014.

It is evident that Putin has pursued his goals consistently and tenaciously. One example is his focused effort to prevent a feared loss of Russia’s second-strike capability after the American withdrawal from the ABM Treaty in 2002. At the beginning of the 2000s, Russia was still too weak to counter the missile defense with something effective. Yet, from the start, Putin aspired to be able to overcome the American missile defense with new means of delivery. But it took time; it was not until 2018 that Putin unveiled novel systems that would achieve this goal, including a hypersonic missile, a new and more capable heavy intercontinental ballistic missile, and a nuclear-armed underwater torpedo.

And Putin presumably also long focused on the West giving in on the NATO enlargement issue and on additional assurances and arms control agreements taking account of Russian interests and demands. The diplomatic process he initiated in 2021 and the draft agreements Russia proposed in December 2021 setting out Russian demands to the United States and NATO testify to that.

At the same time, however, he was also ultimately prepared to use military means to achieve his goals once the Russian armed forces had regained strength. Even though he miscalculated and was thoroughly mistaken—as far as the capabilities of the Russian armed forces, Ukraine’s will to defend itself, and the West’s resolute reaction are concerned—he still appears to unflinchingly stick with his goals in the Ukraine War. It is questionable whether he will succeed, but that cannot be completely ruled out. In any event, Putin still seems, despite enormous economic and human costs, to bank on prevailing in the end, unwilling to be humiliated.

The Ukraine War has once again made it clear that the world order is subject to a dynamic process of change. The Cold War bipolar world order is long over. And the unipolar moment, which the U.S. administration assumed it had and could use to impose its will in the 2000s, and at least partly during the erratic foreign policy under President Donald Trump, is also history; it only demonstrated the effects of a blatant overestimation of America’s possibilities and capabilities.

For years now, the United States has been focused on Asia and its fast-rising rival China. And it should not have come as a surprise that in view of China’s aggressive foreign policy and her determined and rapid military buildup, NATO’s new strategic concept, adopted on June 29, 2022, for the first time, contains clear passages on China’s policy, which is squarely directed against the interests of the alliance. Today, instead of the old bilateral bloc confrontation that the sides have become accustomed to and settled in for, we are faced with a deepening multipolar rivalry between the great powers.