Sir Alec Douglas-Home said the Soviets move when they see an opportunity. They always have. Like a knife, they push ahead when they hit butter, and back away when they hit steel. Soviet policy seeks a "maximum of confusion and a minimum of commitment.” Putin is following closely in the KGB tradition.
Luckily, unlike the USSR, Putin does not even vaguely desire to change or conquer the world. I don't think the USSR was an existential threat to the West. Putin certainly isn't. So don't be distracted by fears about Russia. Because existential threats do exist.
Russia is a threat but not an existential one. It's also a declining regional power with big problems and a lot of H-bombs. Putin is bad news, but we are being manipulated to see him, Iran and Assad as the big threats. Meanwhile a revolution is happening among Sunni Muslims which in a few years will bring probably people like Marine Le pen to power. Some Sunni Muslim ideas and some Sunni states are bigger threats than Russia.The biggest threat is an inexorable movement into Europe from Africa and Asia.
Russia will be a danger after Putin goes, if order breaks down.