With the collapse of the nuclear ceiling... ambiguity is an international existential crisis.

The end of New START removed the last legal ceiling limiting strategic nuclear proliferation between the United States and Russia.

The treaty limited deployed strategic warheads to 1,550 and deployed delivery systems to 700, linking these numbers to mechanisms for data exchange, notifications, and inspections. With its expiration, the risk of mutual nuclear annihilation becomes more imminent, shrouded in uncertainty and danger.

The demise of New START reveals two facts: First, verification had been crumbling for some time, including Russia's suspension of its participation in February 2023. As a result, the "trust but verification" mechanisms collapsed.

Second, the complete termination of the agreement removes the ceiling on the nuclear arms race; when the limits disappear, the parties race to plan for the worst-case scenario, and the option of “raising up” – that is, increasing the load of nuclear warheads on existing missiles – becomes the shortest path to strengthening deterrence.

However, this approach dangerously shortens the warning time and pushes crucial decisions closer to the field.

The SIPRI Institute warns of new dynamics and complexities in the arms race. As the international nuclear environment moves toward modernization and expansion, China’s arsenal and infrastructure are growing at a remarkable pace. Stability is no longer a bilateral issue, but a trilateral one, and perhaps even more complex. While China refuses to engage in any new treaties to curb the race, this provides Washington and Moscow with a pretext to attach broader conditions to any future treaty, making it more difficult and more fragile to implement.

In the short term, the breakdown of verification mechanisms poses a serious risk, as the absence of measurement tools increases the likelihood of miscalculations: false alarms and false reassurances. This creates a "spiral of uncertainty": less inspection means less certainty, less certainty means more caution, and caution justifies further secrecy and misjudgment of adversaries' intentions.

The effects of this uncertainty are first felt in Europe, not because it will become a nuclear power tomorrow, but because it will become more vulnerable to error. Geography shortens European decision-making time and amplifies the sensitivity of signals. The war in Ukraine is prompting some capitals to reassess deterrence, not as an abstract concept but as a political guarantee. This is intensifying debates about European "strategic autonomy," the role of the British and French arsenals, and the viability of "nuclear sharing" arrangements within NATO. The idea of deploying additional capabilities or expanding deterrence infrastructure may resurface as a direct response to this ambiguity.

Conversely, Europe also has a rare opportunity: to fill the void of technical diplomacy with confidence-building measures that are less ambitious than treaties and more realistic than slogans, faster channels for crisis management, reduced chances of error, and rules to prevent accidents at sea and in the air.

The vacuum in the Middle East is reflected not through an open arms race, but through the "value of choice." In a region where crises are fueled by ideological conflicts and crises of confidence, mutual suspicion grows, the missile environment accelerates, and conflicts intensify. This increases ambiguity and diminishes the moral and political incentive for restraint. Therefore, investing in a "latent strategic nuclear capability" becomes more attractive: nuclear fuel infrastructure, engineering expertise, missiles, and command and control systems, which can reduce the potential breakout time should the strategic environment deteriorate or safeguards collapse.

However, the absence of a treaty does not necessarily mean an automatic arms race in the region. Large-scale expansion is costly, nuclear industries are not limitless, and the second-strike capability—especially from submarines—remains a crucial deterrent. But the real danger is closer: that the great power competition will be conducted in an atmosphere of ambiguity, leading to a reshaping of the behavior of allies and adversaries based on the worst possible interpretation.

While a “grand bargain” now seems out of reach, “smaller deals” remain possible and may save something more valuable than the ceiling: stability in the crisis, through missile launch notifications, hotline updates, rules to prevent accidents, and calculated voluntary transparency.

These tools may not bring back the era of treaties, but they can reduce the likelihood of miscalculations. In nuclear policy, it is not only the danger itself that kills; it is often ambiguity and miscalculation that are deadly.