[1] He publishes on the conduct of British Army operations in World War I, and contributes to print and broadcast media on the subject.
[2] Sheffield is a proponent of the "revisionist school" of thought with regard to the conduct of military operations on the Western Front by the British Army during the First World War.
The British literary academic Frank McLynn, in a book review in The Independent, said Sheffield was a " single-minded Right-wing ideologist" who had "tied himself in illogical knots" to "rescue (Douglas) Haig from the justifiable charge of being an incompetent butcher" and "launder" his reputation in an "eccentric and cocksure work" that was "an insult to the memory of the soldiers who had died in droves under his command on the Western Front.
Whether it will change public opinion is another matter, but when (in the distant future) the ruler of history - and not weight of emotion - measures the Great War, I feel sure that Gary Sheffield's views will be firmly amongst those which predominate".
Reviewing the book in The Daily Telegraph the historian Nigel Jones commented on its 'solid scholarship and admirable advocacy', yet added that (with reference to Sheffield's thesis that the extremely high casualties of the British Army can be partly explained by Haig's understandable lack of experience in such matters in the years 1914 to 1917): 'the nagging thought remains: what a terrible shame it was that Haig's progress along his learning curve had to be greased by such deep floods of blood.