The claim that military power helped cement Napoleon's dictatorship, which Wikipedia plays with, is somewhat misleading. While successes in Italy and Switzerland certainly gave Napoleon a good deal of luster, the victories of Marengo and Hohenlinden (notably not fought by Napoleon) were a capstone to Napoleon's accumulation of more executive power, not its cause. Napoleon in these years was an incredibly adept master of bureaucratic minutia and politics, and this allowed him to sideline both his main Brumaire conspirators.

Sieyès himself fell victim to seeing Napoleon as a purely military figurehead, and this underestimation was much of his undoing after Brumaire. Sieyès claimed in the waning years of the Directory that "I need a sword," and Napoleon was one of several generals who could conceivably be used to end the Directory. A military general could command the loyalty of one of the few powerful institutions that possessed a great deal of popular legitimacy within the Republic, the army. Bernadotte, a general and Minister of War, was the favorite of the Neo-Jacobin factions that wanted to reestablish the Revolution's leveling tendencies. Jean-Baptiste Jourdan toyed around with many different factions. Lazare Hoche, who enjoyed almost as much fame as Napoleon had unfortunately died of tuberculosis before Sieyès's initial soundings towards him could bear fruit. Jean Moreau, the youngest general in the army, refused to compromise himself with politics despite entreaties to do so.

For Sieyès, Napoleon was the safest of his "swords." Napoleon's army was trapped in Egypt, so there was seemingly little danger of him acting like a Sulla or Vespasian and using the army to erect a dictatorship. Napoleon's fame from Italy had given him a degree of clout within France, but he was still a relative stranger for the Army of Germany. But even though Italy was a relative sideshow for the French Revolutionary Wars, it allowed Napoleon to gain practical political experience, and in particular, his erection of the sister republic in Italy led him to appreciate the nuances of constitutional wrangling and networking among elite factions.

It was Napoleon's ability to master back channel politics, and less his considerable martial talents, that allowed him to outmaneuver Sieyès and his fellow conspirators. Napoleon insisted on chairmanship of various committees for the formation of the Consulate's bureaucratic and executive structures, and he was thus able to influence them to create the mechanisms for very strong executive leadership. Sieyès in this regard was undone by his own overly complex schema for state power and his overestimation of his political abilities. The morning after Brumaire, Boulay de la Meurthe asked Sieyès if he had a constitution in mind for the new government, upon which the latter admitted he did not. Sieyès then launched into a frenetic proposal for a constitution over the next several days. These proposals were so labyrinthine and convoluted, that they played into Napoleon's hands. The General's experience in Italy had taught him the virtue of simple, direct governments, and the sister republics he erected had constitutions struck a fine balance between vagueness and clear enshrinement of power (one of Napoleon's alleged axioms was that constitutions should be short and obscure). Sieyès's vision of how the Consulate should function was a confusing mishmash of rotating power, Enlightenment pipe dreams, and overly complex diffusion of legislative and executive authority. In contrast, Napoleon's proposals for the Consulate were a model of simplicity, but also enshrined a good deal of power into the First Consul.

Napoleon's maneuvering in the post-Brumaire period was quite astute in that he was a vague enough in his ideological predilections he could appeal to many different factions, and his pragmatism towards running a government won him many converts among the middling strata of French political life. The price of the stability Napoleon promised in the Consulate was dictatorship in all but name. Napoleon also appreciated that he could afford to be magnanimous to individuals he outwitted in this process, and Sieyès was one of them. Sieyès received a fat sinecure from the French state in exchange for his ultimate political irrelevancy.

But Napoleon's preferences for "vague and short" constitutions proved a double-edged sword for the dictator over the long term, as did retiring off political rivals. In the latter case, Sieyès formed part of an incipient social circle of French elite who were ill-disposed towards Napoleon. The ranks of these informal circles swelled under the Empire and provided a ready-made opposition who knew the ins and outs of the French legal and governmental system when Napoleon's fortunes began to wane. The Consulate and Imperial structures encouraged a promotion based on merit and ability, but Napoleon's desire to monopolize political power onto himself meant there was a glass ceiling within the French government, that further alienated Napoleon from his own elite. Thus while he awarded titles and various other rewards to his servitors, they became more of a liability to their recipients; noble titles, for example, necessitated incomes to match, and the parsimony of the Emperor meant a number of the Napoleon nobility grew poorer as their social status allegedly improved. Cutting these elites off from alternative forms of compensation like actual political power, made them more susceptible to oppositional social circles or to not be terribly invested in the Empire's political future. The vagueness of Napoleon's constitutions also meant that it was easy to dispose of Napoleonic rule by using the same vagueness against the Emperor, which the Senate did in 1814. In the end, although Napoleon's adroit mastery for accumulating power allowed him to sideline potential rivals, those very same tendencies also prevented the Napoleonic system from developing anything but shallow roots in French government and high society.

Sources

Broers, Michael. Napoleon: Soldier of Destiny. New York: Pegasus Books, 2015.

Dwyer, Philip G. Napoleon: The Path to Power. New Haven, CT: Yale University Press, 2008.

Woloch, Isser. Napoleon and His Collaborators: The Making of a Dictatorship. New York: W.W. Norton, 2001.