1945 changed the face of war forever. The dropping of the first two atomic bombs raised man's capacity for destruction to a new dimension; although it had always been quasi-limited, now, thanks to the mastery of the atom, what had previously required time and persistence could be achieved in barely a second, as was so cruelly demonstrated in Japan.

The effectiveness demonstrated by the American atomic bomb aroused in other actors the desire to acquire a nuclear capability of their own, initiating a degree program among them, not so much for the sake of destroying their enemies, but rather to persuade them of the high cost they would have to pay if they decided to attack them. This is how the concepts of nuclear proliferation and deterrence were born.

Aware of the possibility that irrationality, error or even human malice could lead to annihilation, the United States and the USSR weaved a network that culminated at the end of the Cold War in a plethora of treaties that sought to reduce such a possibility. The climate of cooperation that followed the confrontation between the two superpowers gave hope for a world without nuclear weapons. However, at the turn of the 21st century, this atmosphere gradually changed into one of confrontation that has ended up dismantling, almost completely, the nuclear arms control regime to give way to a scenario in which the contours of a new degree program even more complex than the previous one are being drawn.

The current instability encourages many actors, for reasons of security, ambition or prestige, to strengthen their power by acquiring atomic weapons, even in the face of the international civil service examination . This proliferation trend is manifested in two dimensions: a horizontal one, which widens the issue of countries in possession of atomic weapons, and a vertical one by which those who already have them reinforce their arsenals.

Iran is the paradigm of the first dimension. For various reasons, the country has been trying for years, even if it denies it, to acquire an atomic bomb. International pressure in the form of economic sanctions forced Tehran to sign in 2015 the "Joint Comprehensive Plan of Action" (JCPOA) whereby, in exchange for the lifting of sanctions, it accepted limits to its nuclear program, and a more stringent inspections regime. The plan was denounced in 2018 by President Trump and, since then, Iran has enriched and stockpiled uranium above the agreed limits until it has reached a threshold at which it could easily build a bomb.

Iran is not the only case of a proliferator state. In the same region, Iran's maneuvers are worrying other powers such as Saudi Arabia, a direct rival of the Shiite regime, which is contemplating the possibility of moving towards an indigenous nuclear capability. Eloquently, before the October 2023 massacre in Israel, the Saudi regime had asked the United States for support for a peaceful nuclear program as one of the quid pro quos for its eventual accession to the Abraham Accords. Meanwhile, in Asia, the nuclear power of China and North Korea, and the increased uncertainty about the US commitment to their security, is leading South Korea to consider the desirability of becoming a nuclear power. And, although it has not yet done so, proliferation could spill over to Europe in the face of Russian aggressiveness, if the continent perceives the nuclear deterrent provided by the United States to its NATO allies as insufficiently credible.

issue In the vertical dimension, China is making efforts to provide itself with a second strike capability by increasing the number of nuclear warheads in its arsenal, and through the development of a "triad" of mobile means to improve the survivability of its arsenal. Russia and the United States, for their part, are proceeding to modernize their capabilities in order to position themselves in the multipolar world that seems to be emerging.

Few brakes stand in the way of this process. Perhaps the most solid is the 1968 Non-Proliferation Treaty (NPT), which, despite its limitations, has been a dam against proliferation. Today, however, the lack of political will, the climate of insecurity, the fact that some nuclear-weapon states have not signed it or have withdrawn from it, and the reality of the unfulfilled promise to move towards a world without nuclear weapons, have undermined its credibility and raise fears of its failure. The New-START, signed by Russia and the United States in 2010 to further reduce their respective arsenals, is unlikely to survive beyond 2026. Finally, the Treaty on the Prohibition of Nuclear Weapons (NPT) promoted by the UN General Assembly and in force since 2021, unrealistic and far from universal adherence, does not seem to be the instrument that will rid the planet of atomic weapons, although its capacity to create an international rule against their possession should not be underestimated.

The deteriorated international environment constitutes an ideal breeding ground for a new degree program that would once again bring humanity closer to the precipice of its self-destruction. As it was done in the past, it is urgent to articulate again a new procedure of management of crisis, adapted to the current geostrategic reality, to prevent such a possibility from materializing.