On 24th February 2022, Russia began its full-scale invasion of Ukraine. While the phenomenon of a stronger nuclear-armed state going to war with a less powerful non-nuclear armed state is far from unprecedented – even in the 21st century – the overt nuclear dimension to this conflict feels different to those in Afghanistan, Iraq, Georgia, Libya, and Syria, and even to the Russian annexation of Crimea in 2014. 

This is because nuclear threats, nuclear signalling, nuclear coercion, and nuclear deterrence have played a central role in how the conflict is playing out. None of the previous conflicts of the 21st century have included thinly veiled threats of nuclear use on this scale, and none of these conflicts involved such close interaction between nuclear-armed protagonists (Russia and, indirectly, NATO).