Diary: Deep secrets from before the Cold War thaw

When a batch of previously classified government papers was released under the 30-year rule three weeks ago, attention was mostly focused on what they revealed about the urban riots of 1981. On the day, everyone missed a Cabinet file that demonstrated how frighteningly real the prospect of nuclear war was thought to be back then – but it did not escape the sharp eyes of the historian Peter Hennessy, aka Lord Hennessy of Nympsfield.

The file shows that every two years officials rehearsed a "transition to war" drill in which they role-played ministers having to cope with a nuclear attack by the Soviet Union. At its climax, the civil servant who stood in for Margaret Thatcher declared that "never before had a Cabinet been faced with such a grim choice between capitulating to a powerful and malevolent aggressor and embarking on a course of action that could end in the destruction of civilisation," Hennessy told the House of Lords, during a debate on freedom of information.

This exercise was wrapped in deepest secrecy because if the public had known the risk of a nuclear attack was taken seriously, opposition to the arrival of Trident missiles on these shores would have escalated.

People in high places understood that the presence of so many nuclear weapons on these islands made them the Soviets' No 1 nuclear target. That was why the Germans did not want Trident on their soil. Thatcher, being the Iron Lady, volunteered to take the risk. But she did not want to share this knowledge with the public.

Thirty years on, the Government is desperately pruning the defence budget; one in eight Gurkhas faces redundancy. But one subject that is just not open to debate is whether we really need to sink billions into renewing the UK's nuclear weaponry.

Spectator puts Ed on the block

The campaign to unseat Ed Miliband takes another turn today with the appearance on the front of the Tory-supporting Spectator of a cartoon depicting the Shadow Home Secretary, Yvette Cooper, as the Iron Lady. If by some process she did take over the Labour leadership, a whole new press drama would open up about who rules the Balls-Cooper household, and it would be more complicated than the story of the Miliband brothers.

Other front-rank women politicians – Thatcher, Theresa May, Margaret Beckett, et al – have or had supportive, self-effacing husbands who stayed out of sight. Ed Balls would doubtless be supportive, but never out of sight.

The simple answer, one Labour MP who is prominent in the "Any Leader Who's Not Called Ed" camp told me, would be for Yvette to pack her husband off to a senior job in Europe. But would he want to go? I think not.

Show some respect please, Mr Cameron

David Cameron showed why he is known as Flashman at the end of Prime Minister's Questions yesterday. Replying to a question from Labour's Dennis Skinner about the Leveson Inquiry, the Prime Minister gratuitously remarked that he had told his children they need not go to the Natural History Museum to see a dinosaur when they could see one in the House of Commons.

Skinner, the MP for Bolsover since 1970, will be 80 in three weeks. There is indeed much about him that is changeless and resonant of a different era. He remembers his mother taking in washing during the 1930s because mine owners had sacked his father for his part in the 1926 strike. There were 700 mines in Britain when Skinner started work in one of them, in 1949. When he took up his seat in the Commons, Cameron was three years old. Skinner was making trouble from the Labour benches for Margaret Thatcher all through Cameron's time at Eton College.

You can see why Cameron would think it a good joke to face an opponent whose politics are rooted in the Great Depression but Thatcher always respected Skinner. After she resigned, she paid tribute to him as a "great parliamentarian". It's something Flashman would not understand.

Blair is spun out as aide Doyle departs

Tony Blair's long-serving spokesman, Matthew Doyle, is leaving without another job to go to, PR Week reports. Doyle has been with Blair since 2005, having previously worked for the Labour Party and as special adviser to David Blunkett, until Blunkett's second forced resignation. It may mean nothing, or it may mean something, but Doyle was spotted last week locked in conversation with Ed Miliband's chief spinner Tom Baldwin.