On October 8, 2026, Aleksandar Matovski presented at a Rethinking European Development and Security (REDS) seminar, co-sponsored by the Center on Democracy, Development and the Rule of Law (CDDRL) and The Europe Center (TEC), on Russia’s nuclear escalation and restraint during the war in Ukraine. The central puzzle he sought to explain was why the severity of an external shock does not necessarily correspond to the timing or intensity of Russia’s response. Moscow has repeatedly resorted to nuclear threats and provocative signaling. Yet, at other times, it has absorbed substantial military setbacks without responding with comparable ferocity. The question, therefore, is what explains this variation in restraint and escalation.

Matovski identified three broad explanations in the existing literature. The first concerns external constraints, including backlash from Russia’s remaining partners, the limited battlefield utility of nuclear weapons, and the danger of confrontation with NATO. However, these factors primarily explain restraint rather than escalation. The second concerns credibility decay, whereby repeated threats without follow-through undermine credibility and encourage riskier behavior to restore it. The third concerns domestic political influences, including hardliner pressure, regime survival threats, and risk-averse elites and citizens. Interestingly, domestic politics can generate both escalation and restraint. The question is which pressures matter, when, and how they interact with external constraints.

Matovski consequently proposed his pressure cooker framework, based on three premises. First, Putin needs a “forever war” to maintain political control. Continued confrontation allows the regime to mobilize nationalism, justify repression, and redirect dissatisfaction toward foreign adversaries. Second, military failure does not necessarily imply domestic political failure. Much depends on how the Kremlin frames setbacks and manages their political consequences. Third, nuclear coercion is essential to sustaining the war. It discourages Western intervention and reinforces the domestic narrative that Russia cannot ultimately be defeated.

The mechanism begins with an external shock, followed by initial restraint and the gradual accumulation of political pressure. Initially, restraint may be advantageous because escalation can publicly acknowledge military failure, alarm risk-averse citizens, and create further external risks. The Kremlin can also temporarily defer the political costs of inaction by controlling the narrative. However, as setbacks accumulate, hardliners increasingly interpret restraint as weakness. Meanwhile, the wider public may question the war’s sustainability. Repeated unenforced threats also undermine Russia’s credibility and may encourage adversaries to test its limits. Eventually, the political costs of restraint may outweigh those of escalation, prompting more dramatic action.

Matovski illustrated this through the 2022 mobilization and nuclear scare. Despite the failure of Russia’s initial invasion, Putin initially avoided large-scale mobilization. However, following further setbacks, particularly Ukraine’s Kharkiv counteroffensive in September, domestic pressures arguably intensified. Putin subsequently announced partial mobilization and the purported annexation of four Ukrainian regions. Russia also intensified nuclear threats. In October, Moscow made allegations concerning a potential Ukrainian “dirty bomb,” amid heightened fears of nuclear escalation. Yet Russia subsequently withdrew from Kherson in November without nuclear retaliation. Matovski interpreted this sequence as consistent with his argument that escalation follows accumulated pressures rather than necessarily responding immediately to individual setbacks.

The central implication is that Russian restraint and escalation may represent different phases of the same political process. Apparent restraint may therefore be unstable, making subsequent escalation difficult to anticipate.