This well-done book suggests that the activities of the venerable scientist, diplomat, and politician in Paris during the War of Independence were probably the decisive factor in American victory. Reluctant to break with the Empire during his 1773-74 mission to London, Franklin then resolved to consummate ""the greatest revolution the world ever saw."" He spent the years from 1777 through 1785 consolidating French financial and diplomatic aid to the rebels, and recruiting European individuals to the cause--an utterly presumptuous undertaking for a leader of a federation without a currency, a standing army, or a navy. Schoenbrun also describes Franklin's meetings with leading scientific and literary figures including Lavoisier and Parmentier (though no profundities were exchanged with the 84-year-old Voltaire), making it clear that Franklin was no aged rake in a funny fur hat, but an eminence preceded by his reputation in physics and political economy. The book wittily describes efforts to undermine Franklin's French alliance on the part of fellow diplomats like John Adams and Arthur Lee, who were sent ""instead of the workaday consuls and naval administration experts that Franklin pleaded for."" More appreciative of Franklin than Bendiner's The Virgin Diplomats (p. 866), more substantial and enjoyable than Hawke's Franklin (p. 364), this study underlines the essential role of great-power assistance and Franklin's skill in obtaining it as a triumph, not a pragmatic intrigue.