For smaller powers, the Russia-Ukraine War’s lesson may be that their security will depend on nuclear deterrence.

The expansionist ambitions of the three most powerful countries in the world—China, the United States, and Russia—are undermining the current world order. Since its founding, the People’s Republic has expressed interest in Taiwan; Beijing may now be on the verge of attempting to conquer the island. Somewhat less seriously, in January, the newly inaugurated President Donald Trump announced his intention to incorporate Canada and Greenland into the United States.

The most consequential driver of the erosion of the post-war order over the past eleven years is Russian behavior. Since 2014, Moscow has launched a campaign of land grabbing and, since 2022, an invasion with genocidal characteristics on Ukrainian territory. As a former Soviet republic, Ukraine was a founding member of the UN in 1945. It has been an official non-nuclear-weapon state under the Non-Proliferation Treaty (NPT) since 1996.

For over three years, politicians and strategists from other revanchist powers have observed the course of Russia’s attack and gauged the reactions of other states and international organizations. Relatively weaker countries are learning from Ukraine’s experience that they cannot rely on international law, organizations, and solidarity, and they should not make the mistake, as Kyiv did, of trusting “security assurances,” “guarantees,” “friendship treaties,” “strategic partnerships,” and the like. Such agreements are of little significance, as demonstrated by the irrelevance of Ukraine’s respective agreements with Russia (1994, 1997), China (2013), and the United States (1994, 2008).

The standard solution to the security dilemma of smaller powers is to join defensive alliances, ideally ones that include at least one nuclear-weapon state. But as Tbilisi and Kyiv, among others, have learned the hard way, gaining full membership in a powerful defence alliance is neither easy nor risk-free. In response to Georgia and Ukraine’s applications for NATO membership in April 2008, the alliance told them that they would “become members.”

What followed, however, was neither their accession to NATO nor the start of a process of admission to the alliance, the Membership Action Plan (MAP). Instead, Georgia has been dismembered by Russia since 2008 and Ukraine since February 2014. The only consolation for the two countries may be that Moldova, also a post-Soviet republic, but a constitutionally neutral state with no ambitions to join NATO, has also been dismembered by Russia for more than 30 years. The fate of Finland, which has a long border with Russia, serves as a counterexample: Unlike Georgia and Ukraine, Finland successfully initiated a NATO accession process in 2022, culminating in its accession in 2023.

The examples of Finland and Moldova show that a former Russian colony’s intention to join NATO is neither a sufficient nor a necessary condition for a Russian invasion. All other things being equal, Georgia and Ukraine would probably have become targets of Russian expansionism, like Moldova, even without an aspiration to join NATO. 

They could have only avoided losing their territorial integrity to Russia by submitting to the Kremlin, through entry into the Moscow-dominated Eurasian Economic Union and the Collective Security Treaty Organization. Ukraine would likely have been pressured to co-sign the 1999 Union Treaty between Russia and Belarus.

The experiences of Ukraine and Georgia with NATO and Russia’s response to them illustrate the risks associated with attempting to join a powerful international coalition. External balancing is complicated and can provoke the interventions they are intended to prevent. This is especially true for those states that are in the most in need of security guarantees.

The current geopolitical upheavals stem from the competition among Russia, China, and the United States—the three most powerful nations, permanent members of the UN Security Council, and the largest official nuclear-weapon states under the NPT. This undermines confidence in both the future behavior of relatively stronger states and the continued relevance of international law and organizations for protecting relatively weaker countries from major powers.

Today’s transformations may seem unproblematic from the perspective of Beijing, Washington, and Moscow. However, it is likely to cause concern among non-nuclear-weapon states with little international integration. Countries that have potentially expansionist neighbors and operate outside NATO or other relevant defense alliances must now rethink their national security strategies. The leaders of China, the United States, and Russia can ignore, dismiss, or take seriously these reactions to their expansionist ambitions. As long as they do not take preemptive steps to counteract them, a backlash from smaller powers can be expected sooner or later.

One possible reaction to the end of the postwar order could be the increased acquisition of weapons of mass destruction for deterrence and defense purposes. Such decisions could, in turn, trigger similar steps by their neighbors, who distrust the accumulation of weapons of mass destruction on their own borders. This could trigger regional arms races and a domino-like proliferation of weapons of mass destruction. The influx of nuclear, chemical, and biological weapons into state arsenals, in turn, increases the likelihood that such weapons will also fall into the hands of non-state actors.

The changes in global security policy triggered by Russia’s territorial expansion and multiple war crimes in recent years raise existential questions for smaller powers. This effect intensifies with each day that the war continues. It would increase dramatically if Russia were to achieve a military victory or impose an unjust Siegfrieden (victorious peace) on Ukraine. Relatively weaker countries bordering potentially expansionist states may come to question their commitment to non-proliferation.