In war, according to the cliché, truth is the first casualty. In fact, as the EU referendum campaign illustrated, truth can also be a casualty in peacetime.

But there is something about the wartime suppression of truth in favour of propaganda that makes it especially fascinating. And, as a corollary, analysing it helps us to understand its continuous use.

So the forthcoming publication of a book about the propaganda employed in the second world war* can be read as both a history and a contemporary media study.

Several questions haunt its lavishly illustrated pages. Were the Britons who lived through that dark six years from 1939 really duped by the all-pervasive propaganda, or did they see through it? Did it affect the outcome of the war? Was it worth the effort and resources devoted to it?

David Welch’s book, Persuading the People, highlights the way in which Winston Churchill’s government unashamedly manipulated the British population in order to ensure victory over “Hitler’s evil Nazi regime”. Those previous four words were, of course, a classic propagandistic formulation of the time, and remain so to this day.

Little was left to chance by the ministry of information, the government’s weapon of choice to exhort the country to pull together and maintain a stiff upper lip.

It appears that the people were open to persuasion and the ministry’s slogans, promulgated through posters and in compliant newspapers, became part of the nation’s conversation.

Britons did “dig for victory” (to improve agricultural output). They did “make do and mend” (to preserve clothing). They did acknowledge that “ploughing on FARMS is as vital as ARMS.” Even if they didn’t really believe it, they appeared happy enough to say to each other “careless talk costs lives.”

Many thousands of women responded to the call for “Eve in overalls” to take up factory work, just as they did to join the forces (“Eve in khaki”).

Welch, professor of modern history at Kent university, has shown how the ministry’s stream of propaganda managed to boost morale by encouraging a sense of community at local level while, at national level, reinforcing a patriotic ethos.

He records how, running in parallel, there was a ready acceptance of propaganda that demonised the enemy through crude national stereotypes - the brutality of the Germans, the cowardice of the Italians and (to a lesser extent, because the truth had yet to emerge) the barbarity of the Japanese.

In 1941, the BBC took the lead in promoting the “V for victory” campaign in which listeners in Nazi-occupied Europe were urged to scrawl the letter V wherever possible. It then took off in Britain after Churchill adopted it.

One of the most interesting sections is devoted to the creation of myths, such as the “miracle” of the Dunkirk retreat, the Battle of Britain fought by “the few” and the supremacy of Bomber Command. They remain part of the British story.

The credit for the success of the lengthy propaganda war goes to the ministry of information and to the wisdom of politicians who realised that it was more effective to bend the truth - to spin it, to employ the modern term - rather than suppress it.

Along the way, the truth was often concealed because the propagandists found ways to turn reverses into triumphs (Dunkirk, for example). Yet there was no single person, a Svengali figure, at its helm.

Journalists, such as the Daily Mirror’s columnist Cassandra, did occasionally rail against the subtle censorship by mocking the ministry. But, like their readers and the overwhelming majority of the population, they largely accepted that the greater good was served by accepting the restrictions.

The ministry was staffed by a shifting cast of people who churned out an astonishing range of material in order to fulfil the war cabinet’s objective “to help sustain public morale and to stimulate the war effort.”

As Welch points out, one key reason for Britain’s morale remaining high even after the fall of France was “due to Churchill’s leadership and his indomitable bulldog spirit.”

In a sense, Churchill proved to be a walking, talking propagandist. He created his own image and played up to it. And it endures, of course, to this day.

*Persuading the people: British propaganda in world war ll by David Welch (15 September, British Library, £25)