Since 1945 and the first use of nuclear explosives, a conviction has shaped Western strategic thinking: the existence of these “ultimate weapons” makes any war of conquest between major powers unthinkable, rendering the territories of nuclear-armed states inviolable. Therefore, these nations could only engage indirectly in limited wars, whose intensity would never reach the hyperbolic violence of the two world wars.
However, this certainty has been shaken. By invading Ukraine, a country whose independence and security it had guaranteed under the Budapest Memorandum in 1994, Russia used its atomic arsenal as a shield (without risking direct involvement of the United States) to conduct a conventional war of conquest. This Russian invasion has disrupted deterrence mechanisms profoundly, with consequences that may not have been fully diagnosed.
The concept of a nuclear “threshold,” theorized in 1960, assumed a clear line beyond which nuclear war became certain. Since the start of the war in Ukraine, this concept can no longer be strictly understood. In reality, behaviors follow more complex mechanisms: there is an area of uncertainty, an intermediate space where an infinite number of hostile acts remain possible without automatically leading to the ultimate escalation.
In other words, there is an elevationof the threshold at which the behavior of certain actors becomes intolerable. This elevation opens a window of opportunity for “revisionist” powers, meaning those wanting to change the rules of the system to their advantage.
Continued…
