Glasgow-born Niall Ferguson, who is Professor Of History at Harvard University, said the UK would have been better placed to deal with German aggression if it had allowed the war on the continent to run its course and used the time to re-arm.
The remarks come in the year of the 100th anniversary of the start of the conflict, which Britain joined after going to the aid of Belgium when Germany invaded.
Professor Ferguson said: "Creating an army more or less from scratch and then sending it into combat against the Germans was a recipe for disastrous losses.
"And if one asks whether this was the best way for Britain to deal with the challenge posed by Germany, the answer is no. Given the resources Britain had in 1914, a better strategy would have been to wait."