Catherine Bennett is an Observer columnist.

What if Niall Ferguson had not declared war on Pankaj Mishra in 2011? As Ferguson argues in his book Virtual History: "It makes sense to compare the actual outcomes of what we did in the past with the conceivable outcomes of what we might have done."

Thus counterfactualists may want to ask how things might stand had Ferguson not chosen to respond with escalating legal threats to Mishra's unfavourable review of Civilization in the London Review of Books. Mishra had made comparisons with work by the American white supremacist writer Theodore Lothrop Stoddard, which Ferguson chose to interpret as a libellous accusation of racism: "At the very least, Mishra owes me a public apology for his highly offensive and defamatory allegation." He also expressed anger, in a style perhaps more reminiscent of Charles Pooter than Stoddard, at being described as "immune to… humour and irony" (generously, no formal apology was demanded for this additional affront). Now, Mishra's responses only having further inflamed him, Ferguson is threatening the LRB's editor with litigation, telling her, he discloses: "Don't force my hand by forcing me to put it in the hands of lawyers."

Did it have to be this way? Imagine the outcome if Ferguson had contented himself, as countless indignant academics have done in the past, with letters, bitterly addressing Mishra's wrongness as he sees it. That would have been nothing out of the ordinary for a journal which has hosted livelier engagements, or for Ferguson, who would thereby have retained his place in the celebrity firmament as the brilliant telly historian with, by his own admission, a huge talent for grudges. "Get the bastard when the opportunity arises," is a scholarly precept he shared recently with Decca Aitkenhead. "Never underestimate the irate Professor Ferguson." Although he began his first letter of protest to the LRB: "It is not my habit to reply to hostile reviews", this self-restraint is not uniform. A Guardian article by Seumas Milne was described as "a shocking piece of crass misrepresentation"....