In 2001, Queen Elizabeth II conferred a life peerage—Baron Black of Crossharbour—on Conrad Moffat Black, publisher at one time of the London Daily Telegraph and the Chicago Sun-Times, among other papers. Nine years later, he was sentenced to serve what turned out to be three years and two weeks in an American prison for mail fraud and obstruction of justice. He was released just a year ago.

He is, then, a convicted felon and a member (on leave of absence at the moment) of Great Britain's House of Lords.

He is also a writer—a serious and sometimes charming one. His latest book (following publication of biographies of Franklin D. Roosevelt and Richard M. Nixon; he admires both) is Flight of the Eagle: The Grand Strategies that Brought America from Colonial Dependence to World Leadership. It might better be titled Conrad Black's Essential Americans, for this prodigiously researched book (when did he find time for that?), in the Great Man tradition, traces the leaders, mostly presidents, who made us what we are today.

Even though Flight of the Eagle is published by Encounter Books, which specializes in tracts with titles such as How Obama Embraces Islam's Sharia Agenda and Why Coolidge Matters, Mr. Black is fair and balanced much of the time. Consider this praise for FDR:

Roosevelt had infused an economically and psychologically depressed nation with his own vitality, had led it with consummate talent and astuteness, step by step, to overwhelming economic, military, moral, and cultural preeminence in the world, and to the brink of victory over every foreign and domestic enemy...President Roosevelt had made it America's world to lead, a world largely safe for democracy, at last, as long as the United States was involved in it.

He is seriously opinionated. The three Founding Fathers that count the most, he argues, are Washington (the general), Franklin (the diplomat) and Jefferson (the propagandist). But he's not really keen on Jefferson and thinks the Declaration of Independence is just a bit of a fraud. It was Jefferson, he writes, who made the case "that this (the Revolution) was not a grubby contest about taxes, colonial ingratitude, and the rights of the martial victor and mother country (all of which it largely was) and to repackage it as an epochal struggle for the rights of man . . . " Moreover, George III wasn't a tyrant, just a "limited, ill-tempered, and intermittently mad young monarch."

He likes Lincoln too (who doesn't?). “So unassuming and free of egotism was he, that like a great circus performer, it was obvious only after he had left the stage how brilliant his strategic conception, command decisions, and tactical initiatives had been. That, coupled to the nobility of his cause, his infallible mastery of English, and his profoundly sympathetic personality, explains and justifies Lincoln's immense and universal prestige."

Eisenhower, writes Black, "beneath his deliberately contorted syntax and generally agreeable exterior, was a very complicated and sophisticated tactician and strategist." Wilson was "desiccated." So was Michael Dukakis. All those pills Kennedy took might have led to satyriasis. (More likely he was simply Joe Kennedy's boy.) Mr. Black believes that if Kennedy had lived he might have pulled us out of Vietnam. Kennedy "was a good and beloved president, who remains yet in the hearts and imaginations of the nation and the world, nearly 50 years after his tragic death." His successor, Lyndon Johnson, "was a large, overpowering, tactile, and crude man, with a tremendously effective way of bringing those he could influence into line.” He used all these powers to push through the Civil Rights Act.

Black considers Ronald Reagan "one of the most astonishing characters ever to occupy the presidency of the United States." He was "a very affable man and was universally charming, but he was, in the words of media proprietor Rupert Murdoch, 'a cunning old peasant.'" He "stuck to prosperity through the economic growth of free enterprise and lower taxes and peace through strength," Mr. Black says. "He delivered both, and his standing as a president became clearer after he had retired and the scale of his achievement towered over the simplicity of his methods."

Mr. Black ranks Reagan as our fourth-greatest president, following Washington, Lincoln and Roosevelt.

When Mr. Black takes side, he does it with passion. Douglas MacArthur, he writes, was "one of the great military commanders of modern times." His critics, the brilliant military historian Max Hastings writes, believed his Philippines campaign was unnecessary and driven only by his obsession to liberate his "second home." More than ten thousand American soldiers died, another thirty-six thousand were wounded.

He was wrong in Korea too when he promised his soldiers that they would be home by Christmas, dismissing reports the Chinese were massing for an attack on exposed American positions in northeastern North Korea. An obscure Marine general named O.P. Smith led his First Marine Division from the Chosin reservoir to safety, fighting his way through thousands of Chinese troops who surrounded his division, his dead and wounded strapped to the hoods of Jeeps as his troops sang the Marine Corps hymn and marched in formation into their own lines.

Black doesn't concern himself with who these people are but rather with what they accomplished. So it is with Nixon. Black salutes his accomplishments, many of which were impressive, and dismisses his sometimes odious behavior. He makes as good a case for Nixon as anyone could. He does make one curious blunder, though, when he says that Kennedy, Nixon and Gerald Ford all saw combat in World War II. Kennedy and Ford did—Kennedy in a PT boat, Ford in an aircraft carrier. Nixon was in charge of loading and unloading C-47 cargo planes on Guadalcanal and Bougainville.

Our last great president, Black contends, was Reagan. He dismisses the men who followed as for the most part second-raters, and he believes that and the United States, by 2012, "was in full decline." Still, on the very next page, he says the United States "remains incomparably the greatest and most successful country there has ever been," needing only fresh leadership to move forward again. The country, he says optimistically, will come round. "Someone will lead it on with a new purpose more galvanizing than just borrowing for the bovine satiety of fickle appetites, in politics as in consumer goods."

James M. Perry, longtime political writer for The National Observer and The Wall Street Journal, is the author of numerous books on American military and political history.