The timeline sees the United States electing a ultra-isolationism president who withdraws from NATO due to some events happening between them, NATO in turn collapse, A the British-French-West German Alliance is form but is unable to hold the Soviet tide and as a result it is up to the British like 40 years in the past to fight and hold long enough until a new American president is elected who might save the day.
Can we expand this idea and would the British after having fought a land battle in West Europe be able to prevent a Soviet Operation Sea Bear.