Russia's invasion of Ukraine in 2022 has had unintended consequences, including an impact on efforts to prevent nuclear proliferation. The Budapest Memorandum, which aimed to reduce the number of nuclear-armed states, has been called into question. Ukraine's experience has shown that countries with nuclear ambitions are unlikely to give up their weapons, strengthening the case for maintaining arsenals. The war in Ukraine has also inadvertently strengthened the nuclear capabilities of Iran and North Korea, as Russia has relied on their support. The possibility of Ukraine pursuing a nuclear weapons program cannot be dismissed, as trust in the Budapest Memorandum has been shattered. The global nonproliferation regime may be at risk without credible commitments and enforcement mechanisms.