Russia, the United States and China have all built new facilities and dug new tunnels at their nuclear test sites in recent years, satellite images obtained exclusively by CNN show, at a time when tensions between the three major nuclear powers have risen to their highest in decades.
Well probably. After all the permanent members of the UN security council released a joint statement that nuclear war would be bad (sic) roughly two month before the invasion of Ukraine began. With the clarity of hindsight it looks a lot like everybody knew what was going to happen and they wanted to reassure each other.