The expiry of the last remaining nuclear weaponry control accords between Russia and the United States is a major change in the security field across the whole world. New Strategic Arms Reduction Treaty (New START) officially expired on February 5, 2026, eliminating the final legally binding restrictions on the nuclear armories of the two largest nuclear powers in the world. During the newly found freedom of action in the U.S and the Russian long-range nuclear weapons, there are no restrictions which bind these two parties.
Nuclear arms control can be traced back to the post World War II era. In August 1945, the bombing of Hiroshima and Nagasaki, which caused the deaths of between 110,000 and 210,000 civilians, changed the way the world knows war forever. Scientists, policy makers, activists and peace organizations in the subsequent decades had to strive to minimize nuclear hazards, and several arms control treaties were made to ensure the curtailed usage of nuclear weapons and minimization of the possibility of a disastrous war.
One of the best results of these efforts was New START which was signed in 2010. The treaty limited the strategic nuclear warheads of each country to 1,550 and it limited the delivery systems like missiles, bombers, and launchers. It also put in place mechanisms of inspections, data exchange and notifications, which were to enhance transparency and predictability between Washington and Moscow.
The expiry of the treaty has an extra significance since the United States and Russia own close to 90 percent of the global nuclear arms. This means that constraints on their arsenals have international consequences. In the absence of New START, it would no longer be legally enforced that the two countries would not increase the amount of deployed nuclear weapons. Although this does not happen now, both parties can take the technical option of expanding their arsenals relatively fast through the addition of more warheads to the pre-existing missiles and this option might lead to a mutual response.
Treaties on arms control such as New START have traditionally been considered to be stabilizing instruments. The treaty decreased the chances of an abrupt escalation in case of a crisis, by restricting the number of weapons that could be used within a short period of time. The transparency (via inspection and sharing information) served to avoid worst-case assumptions, which can fuel the arms races. The loss of these mechanisms leads to uncertainty and the nuclear-armed states will experience the pressure to retaliate by developing or updating their armies.
The officials of the Russians have already mentioned that Moscow would be happy to keep watching the boundaries of New START one year after its end in case the United States had done the same. This offer has not been taken by the U.S. government. President Donald Trump has shown the desire to strike a new and much better deal and he has shown interest in involving China in new discussions concerning arms control. However, China has declined to join such treaties citing that its nuclear weapons are in comparison much less than those that the United States and Russia have and that the biggest nuclear powers must first disarm before involving themselves in the treaties.
New START expiry underscores the wider issues on nuclear risk reduction efforts. Modernization or arsenal expansion continues to affect all the nine nuclear-armed states raising doubts on long term stability. Although the world without nuclear weapons is an object of a remote dream, arm control measures have long been a powerful initiative to decrease risks and avoid misunderstandings.
With the onset of the post-New START era, the lack of established restrictions highlights the significance of ongoing communication, openness, and risk aversion in order to avoid the re-emerging nuclear arms race and control world security risks.