1. Introduction: International stability, human security and the nuclear challenge

Global security continued to deteriorate throughout 2024. Markers of this persistent deterioration included major armed conflicts in Ethiopia, Gaza, Myanmar, Sudan and Ukraine. Military spending, meanwhile, rose for the 10th successive year and exceeded $2.7 trillion in 2024. Ecological disruption also continued, with 2024 being the first year on record in which the average global temperature was clearly more than 1.5°C above the pre-industrial average. New uncertainties arose in the first quarter of 2025 following the election of Donald J. Trump as president of the United States, which prompted a significant departure from previous US policy and assumptions about global security and relations with allies.

A new nuclear arms race?

The era of nuclear weapons reductions appears to have ended. Bilateral nuclear arms control between Russia and the USA entered crisis some years ago and is now almost over. Revitalized national debates in Europe, the Middle East and East Asia about nuclear status and strategy suggest there is some potential for more states to join the nuclear club. The signs are that a new qualitative nuclear arms race is gear-ing up and, compared with the last one, the risks are likely to be more diverse and more serious. Among the key points of com-petition will be technological cap-acities in cyberspace, outer space and ocean space. Thus, the idea of who is ahead in the race will be even more elusive and intangible, and the old largely numerical formulas of arms control will no longer suffice.

Facing the challenge

With President Trump’s return to the White House, there is a repeat of the para-doxical situation experienced during his first administration, in which none of the three great powers is committed to defend-ing and upholding the world order. China, as a rising power, Russia, as a declining power, and the USA, as a profoundly dis-affected power under Trump, all seek free-dom from the constraints of agreed rules whenever they are inconvenient. One way forward is for medium and small powers to work together in coalitions with like-minded governments on specific goals. Cooperation is of value even when it is not comprehensive. It is a pragmatic, viable approach: the new realism.

A return to an era of reductions to the global nuclear arsenal, however, requires agreement among the three great powers. 
A new, general understanding is needed that nuclear weapons do not buy security and that their existence demands balanced behaviour by political leaders. Initial small steps towards reducing risk could form guardrails against disaster. Together with the voices of an informed public, they could also be part of building pressure on the three great powers to take the next steps in reducing their nuclear arsenals.