It is difficult to think of any politician who has lived to be eighty and still been regarded as a success. What we call a “great” statesman normally means one who dies before his policy has had time to take effect. If Cromwell had lived a few years longer he would probably have fallen from power, in which case we should now regard him as a failure. If Pétain had died in 1930, France would have venerated him as a hero and patriot. Napoleon remarked once that if only a cannon-ball had happened to hit him when he was riding into Moscow, he would have gone down to history as the greatest man who ever lived.

George Orwell (1903–1950) English journalist, essayist, writer [pseud. of Eric Arthur Blair]

Essay (1946-05), “Second Thoughts on James Burnham,” Polemic Magazine
    (Source)

Published separately as a pamphlet, James Burnham and the Managerial Revolution (1946).