Do Russia’s military setbacks increase the risk of nuclear conflict?

THE SPECTACULAR collapse of Vladimir Putin’s army in Kharkiv province has revived concerns that Russia might resort to nuclear weapons. “I fear that they will strike back now in really unpredictable ways,” warned Rose Gottemoeller, a former deputy secretary-general of NATO, “and ways that may even involve weapons of mass destruction.” Ms Gottemoeller, speaking to the BBC, said she was not worried about Russia’s massive intercontinental ballistic missiles, which cross oceans and can destroy cities, but its so-called tactical nuclear weapons. What are these, and might Mr Putin use them if he is losing the war?

Tactical nuclear weapons (experts prefer the term “non-strategic”) are those with relatively small yields. They can weigh in at a few kilotons, or less. The yield of a B61-12, an American weapon with a variable yield, can be “dialled down” as low as 0.3 kilotons if it is to be used as a tactical weapon—around one-fiftieth of the yield of the bomb which destroyed Hiroshima. The explosion of a few thousand tonnes of badly stored ammonium nitrate in Beirut in August 2020 showed how terrible such blasts can be. But they are far less devastating than those of the weapons used in an all-out nuclear exchange.