There are several implications arising from the war in Ukraine, which reflect an increased risk for nuclear conflict between NATO and Russia. First, the decision to invade Ukraine represents high risk acceptance and a propensity for miscalculation. Second, based on the Ukrainian war and the ongoing constraints on its conventional capabilities, Russia is likely to increase its reliance on nuclear weapons, and may even assess that it should use nuclear weapons earlier in a conflict. Third, Russian leadership may assess that NATO’s unwillingness to militarily intervene in Ukraine was related to Russian nuclear threats. Additionally, NATO should not assume that lack of nuclear use in Ukraine would mean that the Russians would not use nuclear weapons in a conflict with NATO. The two-peer problem (discussed more below) also complicates NATO’s conventional superiority and may incentivise Russian opportunistic aggression.
Questions were raised on how to deter a Russian nuclear conflict with NATO, especially how to deter Russian limited nuclear use. There was a proposal to shore up deterrence through increasing conventional and nuclear capabilities, with European allies taking on a greater burden in the conventional domain. On the nuclear side, this could involve supplementing DCA capabilities in order to increase the flexibility, survivability, and readiness of NATO’s nuclear deterrent. This could include more DCA aircraft in the NATO mission, increasing DCA survivability through dispersal, deploying ground-based missiles, or the development of Nuclear-Armed Sea-Launched Cruise Missile (SLCM-N). There was some debate about the deterrence benefits and escalatory risks of this proposal. Further, doubts were raised about the political viability and financial cost of this level of conventional and nuclear expansion for European NATO Allies.
There was also consideration of the scenarios that would lead to Russian nuclear use. The key question for elucidating a deliberate use scenario is when nuclear escalation would be, or calculated to be, in Putin’s interest. One scenario might be a situation in which Putin believes he is losing the war in Ukraine, and nuclear use provides an option to save face. However, it is also important to consider the alternatives to Russian nuclear use in this ‘defeat’ scenario: Putin might try to drag out the war, or rely on chemical or biological weapons, or use nuclear rhetoric. Another scenario that was considered, was a scenario in which Putin fears replacement or assassination; however, there were doubts about whether Putin would have the capacity to order a nuclear strike in this scenario, and whether the Russian military would serve as a backstop. Another possible pathway involves the risk of misperception: that an attack in cyberspace escalates into full out nuclear conflict. One way to mitigate this risk is to set clearer policies about what kinds of cyberattacks against the alliance would trigger Article 5, although this risks creating a permissive environment for everything that falls below that line.