John Mearsheimer, Glenn Diesen: The Rise of a Post-Western World & Russia’s Existential War in Ukraine
by Glenn Diesen [10-17-2026].
Professor John Mearsheimer argues that the liberal international order has collapsed because American unipolarity has given way to multipolarity, restoring great-power competition and exposing the limits of Western power. Russia’s war in Ukraine, the conflicts involving Iran and the Houthis, and the growing economic consequences of these wars demonstrate that the United States can no longer dictate international outcomes and that the West faces mounting strategic setbacks.
The End of Unipolarity and the Collapse of the Liberal Order
The end of the Cold War and the Soviet Union’s collapse created the conditions for the optimism associated with Francis Fukuyama’s “end of history” thesis. During the 1990s, American unipolarity appeared to confirm that liberal democracy and the Western international order would become the foundations of global politics.
However, the American wars following September 11, 2001, and the 2008 financial crisis undermined that confidence. The decisive change came around 2017, when unipolarity gave way to multipolarity, with the United States, China and Russia emerging as the three principal great powers. Since two of these powers are not liberal democracies, the liberal international order could not survive in its previous form.
The transformation also undermines the West’s claim to moral superiority. Liberal democracy was presented as proof that Western countries represented the morally superior side of international politics. Yet Western complicity in the genocide in Gaza, particularly that of the United States, makes it impossible to sustain this claim convincingly. The combination of multipolarity, prolonged wars and the loss of moral authority marks a fundamental departure from the post-Cold War vision.
Europe’s Strategic Dilemma
Europe benefited enormously from American military protection during the Cold War and the subsequent unipolar period. NATO extended the American security umbrella, including its nuclear deterrent, across much of the continent. European leaders have consequently regarded continued American involvement as essential to their security.
Two developments now threaten this arrangement. First, the Ukraine war has poisoned relations between Russia and Europe for the foreseeable future. The conflict will eventually end, but the bitterness will remain, particularly because Russia is likely to emerge victorious. Second, the United States increasingly regards East Asia, rather than Europe, as its most important strategic theatre. A crisis involving China could prompt Washington to redirect substantial resources away from Europe.
Europe therefore faces the prospect of enduring hostility with Russia while losing the American protection on which its security has depended. Its current policy risks producing a devastating defeat not only for Ukraine but also for European states and NATO.
Why Russia Is Winning in Ukraine
Russia regards the conflict in Ukraine as an existential threat and cannot afford to lose. This strategic imperative explains why Moscow is prepared to escalate rather than accept an outcome that leaves the underlying threat unresolved.
Russia’s campaign is increasingly directed at dismantling Ukraine’s economic and military capacity. Attacks on energy infrastructure, transportation networks, communications, supply depots and access to Black Sea ports are weakening the country’s ability to function. Russia’s substantial arsenal of drones and missiles, combined with Ukraine’s diminishing air defences, gives Moscow considerable freedom to strike critical targets.
On the battlefield, Russian forces are advancing methodically, using superior firepower to limit their own casualties. Ukraine, meanwhile, faces severe manpower shortages, while Western financial assistance is approaching political and economic limits. These pressures reinforce one another: Ukraine is losing ground as its economy deteriorates and its capacity to sustain the war becomes increasingly dependent on uncertain external support.
Russia will not necessarily conquer all of Ukraine, but it is likely to achieve an ugly victory, leaving a diminished Ukrainian rump state. Continued Western encouragement of Ukrainian resistance and attacks on Russian infrastructure will intensify Moscow’s determination to destroy Ukraine’s capacity to threaten Russia. The continuation of the war amounts to national suicide for Ukraine.
The Middle East and the Limits of American Power
The conflicts involving Iran and the Houthis further demonstrate the limits of American power. Iran has continued attacking shipping across the Persian Gulf, the Strait of Hormuz and the Gulf of Oman despite the failure of an extended American bombing campaign. Neither military escalation nor economic pressure offers a credible path to Iranian surrender.
Saudi Arabia faces a similarly dangerous predicament in its war against the Houthis, who can inflict substantial damage on its oil infrastructure and economy. Ending that conflict will likely require major Saudi concessions, although securing them will be difficult.
These wars threaten global energy supplies and compound the economic pressures surrounding Ukraine. Donald Trump wants an agreement with Russia partly because restoring Russian oil and diesel supplies would help stabilize international markets. Yet opposition from Ukraine, European governments and American foreign-policy hardliners repeatedly obstructs his efforts.
The central lesson is that wars are easy to start but extraordinarily difficult to end. Leaders must consider not only what they hope to achieve through military force, but also the conditions under which they can escape a conflict. Failure to think ahead can turn an initially manageable war into a prolonged strategic disaster.