What are chemical weapons and what they have to do with the war in Ukraine

LONDON. The alarms of Western services and leaders are chasing each other, with suspicions also expressed by the British Prime Minister Boris Johnson and the American CIA. “There are very worrying signs, the same ones we have already seen before similar attacks in Syria,” Western sources told “Repubblica” a few days ago. After the full-blown threats of nuclear war, is Russia really considering using chemical weapons in Ukraine, as the US and UK fear? And after the clear use of the devastating thermobaric bombs in recent days, how far would Moscow go with the so-called “unconventional” weapons?