The American general holds a glass of whiskey on the rocks in one hand and a pistol in the other, and the drunken, devil-may-care look is enhanced by an unbuttoned collar and a tie tugged to one side.

This is the cover of a book due out Thursday entitled The Operators, with a strapline to trigger alarm bells in the Pentagon: "The wild and terrifying inside story of America's war in Afghanistan." As if the outside story were not terrifying enough. The book is by Michael Hastings, who ended the career of the US military commander in Afghanistan, General Stanley McChrystal, with a fly-on-the-wall portrait in the June 2010 edition of Rolling Stone in which "Big Stan" made derisive remarks about the Obama administration.

In his new book, Penguin USA says that Hastings "takes us on patrol missions in the Afghan hinterlands, to late-night bull sessions of senior military advisers, to hotel bars where spies and expensive hookers participate in nation-building gone awry."

So who is the mystery general on The Operators' cover? It is clearly not McChrystal; his favourite drink is Bud Light Lime. Also, the uniform matches that of his successor in Kabul, and now CIA director, General David Petraeus, a resemblance spotted by the Washington Post, which pointed out the unique set of medals worn by the general in the picture.

Penguin USA says the picture was "in no way intended to portray anyone specifically". Could Petraeus sue? He is one of the two most powerful men in America, and arguably even has the edge over Barack Obama, as he can boast support on both sides of Congress. He is a smooth politician, and a skilled raconteur. But he is more a PowerPoint-obsessed fitness fanatic than the bon viveur portrayed on the cover. The CIA press office is giving nothing away. "No comment," says a spokeswoman, adding that even that was off the record.