“I think [a world war] is absolutely a serious threat,” he said in an interview with Sky News.

“In that sense I think the aftermath of 1907 is as interesting as the 1930s.

“Because after 1907 the foreign ministries, defence ministries, intelligence agencies started to operationalise information – to think that information was essential to the control of military events – and there was a kind of arms race in terms of communications control.

“And we’re seeing that kind of arms race at the moment I think.”