I do not know of Russia ever having threatened to attack the UK or of any reason it would choose to do so. Unlike Britain and others, it has never attacked any country not on, or close to, its borders.
Its population is tiny for its huge size, and declining, while it has vast natural resources.
Many Russians own properties and businesses in Britain and others attend schools here. They would certainly oppose any attacks, which would only galvanise opposition to Putin within Russia.
The IEA has said that keeping the UK defence budget at 2 per cent or more of GDP would necessitate serious reductions in funds for courts, policing etc.
Any hostile acts by a foreign powers would be “cyber-attacks” whose origin would be very hard to discover, let alone prove.
The need is for cool-headed, rational thinking rather than wild imaginings and hysteria.