That risk is notoriously hard to predict. There’s no reliable procedure for assessment or solid evidence on which to base it
Warnings about nuclear escalation in Ukraine are now being issued with increasing frequency and urgency, due to dramatic changes in policy by some of Kyiv’s main western supporters.
Some European countries, including Britain, France, the United States and Germany, have changed course, giving Ukraine the green light to use their weapons against sites within Russia. The latter two limited their permission to Ukrainian strikes aimed at defending Kharkiv province – although, according one report, Joe Biden may even lift that geographic restriction, as well. These steps are responses to devastating Russian strikes on Ukraine, many from points beyond its reach.