This is what Ferguson has done in his compelling car crash of a BBC documentary, The Pity of War. It is worth watching, if only to admire Ferguson's astonishingly thick skin.
The question of whether Britain should have gone to war in 1914 has been hotly debated for much of the past century.
On the surface, these two programmes represent the latest incarnation of this debate. They both wonder what the world would have looked like if Britain had stayed out of the war.
Both ask if Britain had good enough moral and practical reasons for stepping in. But they each approach these questions from radically different perspectives.
Hastings argued that if Britain hadn't gone to war, Germany would almost certainly have won, in 1915 or 1916. This, he claimed, would have been an unmitigated disaster. He painted Wilhelmine Germany as a place only a few shades less evil than Germany under the Nazis: an undemocratic country run by a bullying dictator, in thrall to the military, and prone to committing the most horrific atrocities. He also pinned the blame for the war squarely on Germany's shoulders.
Not so, protests Ferguson. Britain was as much to blame for turning the war into a truly global conflict. Furthermore, Germany was not the monster Hastings makes it out to be, it was actually far more democratically progressive than Britain, which in 1914 still withheld the vote from 40 per cent of its male population.
To imply comparisons between the Kaiser's Germany and Hitler's Germany is quite wrong.
According to Ferguson, if Germany had won the war in 1916, it would not have been so bad: Britain would simply have ended up with a Wilhelmine version of today's EU.
Of the two arguments, Hastings' was less interesting but far more canny. He studiously omitted any mention of the many strong arguments against his point of view. Recent scholarship, for example, has suggested that Germany and Austria were not power-hungry: they were only really reacting against the assassination of Archduke Ferdinand, which had all the hallmarks of State-sponsored terrorism.
Hastings lined up a formidable list of historians to back him up, but did not invite an equally formidable list of historians who disagree with him - Christopher Clark and Richard Evans immediately spring to mind.
Ferguson's view is just as one-sided, but for some bizarre reason he seems only to have invited historians who think his theories are nonsense - some of them the same ones who appeared on Hastings' programme. This is a far more honest approach, perhaps, but it does have the effect of making it look as if no one in the world agrees with him.