Global Nuclear Tensions Surge as Arms Control Collapses and Arsenals Grow

Global nuclear tensions have risen as key arms control agreements collapse and major powers expand their arsenals. The latest NPT review conference ended without a joint declaration for the third consecutive time, highlighting deep divisions over disarmament and monitoring efforts. The International Atomic Energy Agency (IAEA) has lost its ability to inspect Iran’s nuclear sites. Since the U.S. and Israeli strikes in June 2025, Tehran has disabled monitoring systems, leaving satellite imagery as the only—yet unreliable—source of intelligence. Underground activities remain largely undetected, raising concerns about undeclared nuclear progress.

The broader nuclear landscape is also shifting. The New START treaty between the U.S. and Russia expired in February 2023 without renewal, removing the last major constraint on their arsenals. Both nations, along with France and the UK, are now modernising their weapons. Meanwhile, China’s stockpile has grown to an estimated 600 warheads, though still far below Russia’s 4,400 and the U.S.’s 3,700. Iran’s stance adds further uncertainty. Without inspections, the regime is likely to use the prospect of future access as a bargaining chip in negotiations. The ongoing conflict between Iran, the U.S., and Israel has only deepened instability, making any diplomatic breakthrough more difficult.

The failure of the NPT conference marks another setback in global non-proliferation efforts. With inspections stalled in Iran and major powers upgrading their arsenals, the risk of escalation grows. The absence of new treaties leaves few mechanisms to curb the expanding nuclear threat.