Introduction

I first review the theory of preventive war and briefly consider what scholars believe about its prevalence historically. This theory is itself deduced from realist international relations theory, which endures as the strongest explanation of patterns in international politics. Then, I assess whether the major predictions from the theory are present in the case.

The most general prediction of the theory [of preventive war] is that the growing prospect of Ukrainian membership in NATO would seem threatening to Russia in the eyes of the Russian foreign policy establishment, not merely in the eyes of Putin. The prediction is credible because most great powers have historically viewed other great powers on their borders as a threat, and NATO membership for Ukraine would put the United States squarely on Russia’s doorstep. In the post–Cold War period, many Western experts on Russia and national security predicted for years that Russia would see NATO enlargement as a threat.

Second, the theory predicts that declining states should note their changing status and attempt to reverse it if they can. Russian leaders told the West that they would view NATO on their doorstep as a threat. Russian diplomacy and published strategy documents expressed security concerns. They tried to warn NATO off.

Third, the theory predicts that the declining state’s fears should have some basis in fact. I will show that the on-the-ground changes in Russia’s military situation that would attend Ukrainian membership in NATO would prove problematical for Russian security. Moreover, the history of U.S. and NATO military deployments during and after the Cold War suggested strongly that capabilities dangerous to Russia would ultimately move forward into Ukraine alongside NATO membership. Indeed, NATO forces were already regularly turning up in Ukraine. Russian spokespersons and documents warned repeatedly that they observed these developments, feared them, and explained why they feared them. I review evidence to show that their fears of the specific military implications of NATO’s presence in Ukraine were reasonable.

Fourth, the theory suggests that Putin and his advisers ought to have had evidence that NATO membership was a genuine prospect and not simply a talking point. I discuss why Russian observers could have viewed the prospect of NATO membership as an impending development that had been gathering momentum since NATO announced future membership for Ukraine in 2008. Although a steadily deteriorating power position produces preventive motives, growing momentum helps confirm the fears of the declining state. The history of NATO’s relations with Ukraine, reviewed below, also suggested to Russia that ultimate membership was likely. Some have argued that Russia had to know that NATO membership was not likely because there was no Membership Action Plan (MAP), the last hoop NATO aspirants once had to jump through. I will show that NATO was forging so many other connections with Ukraine that the absence of a MAP would not have reassured Russia much.

The theory also predicts that the window of opportunity to do anything about the emerging problem is closing. I will discuss the extent to which Russian observers likely viewed Western military cooperation with Ukraine as proceeding at a pace that would make it increasingly difficult for Russia to do anything militarily to prevent Ukraine’s membership in NATO. “War now,” appeared to be better than “war later.” NATO and NATO member states’ military relations with Ukraine deepened Ukraine’s integration with NATO and improved Ukraine’s combat power, and Russia noticed.

One caveat is in order. A preventive war theory cannot explain the exact moment when a war begins, and I do not try to do so. Instead, it indicates whether the state faces a growing incentive to act. 

Conclusion 

Realist theory predicts the phenomenon of preventive war. Historical evidence confirms that such wars happen. Theorists and Russia experts warned for years that Russia would see NATO enlargement as a threat. They also warned that Russia would be particularly concerned about Ukraine’s membership in NATO. Since 2008, NATO, the United States, and other NATO member states deliberately and consistently developed political and military connections to Ukraine. These relationships with Ukraine have intensified since Russia annexed Crimea and sponsored secessionist movements in the Donbas. It is likely that Russia acted for preventive reasons in 2014, and its attacks were certainly a fillip to the NATO-Ukraine integration effort.

After 2014, there may have been no way for Western powers to calibrate their efforts to improve Ukraine’s ability to deter future Russian aggression without also threatening Russia with the prospect of a new NATO ally along nearly 2,300 kilometers of its land and sea border. But there is also little evidence that they tried to achieve such a balance. 

These observations are especially pertinent as the United States considers its policies in Asia. China is a bumptious rising power, and the United States has committed itself to constraining China’s material power and the global influence that it perceives to be commensurate with that power. U.S. policy is understandable, even prudent. At the same time, however, the United States has chosen to make a stand on Taiwan—a particularly sensitive issue for China. The United States works assiduously to improve both its own ability to wage war in the Taiwan Strait and Taiwan’s own defensive capacity. It also focuses on strengthening a web of alliance support in Asia and abroad to resist any Chinese effort to use force to settle the Taiwan matter. The United States leads the effort to close any short-term military window of opportunity that China might perceive, or perhaps ensure that no such window opens. The United States and its friends must be careful that China does not perceive efforts to improve Taiwan’s ability to defend itself as a shield for Taiwan to gain independence. It would be best if there is no retrospective article ever written on China’s preventive war over Taiwan.
 

AP Photo/Omar Havana.

The opinions expressed in this commentary are solely those of the author quoted.