As we have seen, the Congress of Vienna was not the first such convention to define the legitimate constitutional form of government for member states, but it was by far the most intrusive. The state-nation—a constitutional entity based on the consent of the governed—was replacing the territorial states of the previous century, even though a coalition including territorial states had decisively defeated the most dynamic example of the new form. The third interlocking key to legitimacy lay in recognizing this development by specifying constitutional norms for individual states.
This had begun with the Bourbon restoration. The allies were careful to provide that the recall of the Bourbon dynasty was not an acknowledgment of pre-existing rights (as Pitt's original program might have been taken to mean). Rather Louis XVIII was required to grant a representative constitution (the Charte) and was placed on the throne only after an offer was forthcoming from the French Senate, an institution created by Napoleon. The states that defeated Napoleon essentially shared, or came to share, the state-nation constitutional form of which he was the main European architect. Though he despised Napoleon, Talleyrand appreciated this point. He wrote that
however legitimate a power may be, its exercise nevertheless must vary according to the objects to which it is applied, and according to time and place. Now, the spirit of the present Age in great civilized states demands that supreme authority shall not be exercised except with the concurrence of representatives chosen by the people subject to it…. These opinions are no longer peculiar to any one country; they are shared by almost all. Accordingly, we see that the cry for constitutions is universal; everywhere the establishment of a constitution adapted to the more or less advanced state of society has become a necessity, and everywhere preparations for this purpose are in progress.34
The tsar had announced that he wished representative constitutions in all states, 35 and, as we shall see, the constitution for the German states, the Act of Confederation, included an obligation for all member states to enact constitutions providing for representative institutions. Some states resisted, of course, and some were unable to comply: Austria had no single nation from which it could forge a state-nation; indeed the nationality principle was lethal to its cohesion as a state. The most Austria could manage was to adopt the title favored by state-nations for the head of state; Francis had become “Emperor of Austria,” as Napoleon had been “Emperor of the French,” and as eventually Victoria of England was to become “Empress.” Although Prussian representatives at Vienna had been among those who insisted on the provision for German representative institutions, Prussia too was hesitant. It was but a fragment of the German nation. Prussia could not support the creation of a German state-nation from which she was absent, but Austria and Russia could scarcely support a new German state of which Prussia was a part.
This concern for the domestic composition of constitutional regimes was tied to the issue of legitimacy and thence to stability. Wellington conceded that after the treaty France remained strong enough to overturn the rest of Europe—that, in other words, a balance had not been achieved—but rejected proposals to weaken her territorially through adverse cessions. Such cessions would delegitimate the French government. As Castlereagh put it, punitive reductions would leave “the [French] King no resource in the eyes of his own people but to disavow us; and once committed against us in sentiment, he will be obliged soon either to lead the nation into war himself, or possibly be set aside to make way for some more bold and enterprising competitor.”36 Wellington concurred:
We must… if we [were to] take this large cession [crippling France's war-making power], consider the operations of the war as deferred till France shall find a suitable opportunity… to regain what she has lost… [W]e shall find [then] how little useful the cessions we have acquired will be against a national effort to regain them. Revolutionary France is more likely to distress the world than France, however strong her frontier, under a regular government; and that is the situation in which we ought to endeavor to place her.37
Thus we see intertwined the three issues of the balance of power, the general welfare of Europe, and the constitutional makeup of individual states, all bearing on the crucial matter of legitimacy. Only a Europe composed of stable states, managed by a directorate of the most powerful of these states, with a mandate to act in the interest of the society of states as a whole, would prevent a new outbreak of such cataclysmic war as Europe had experienced for twenty years. Otherwise, the collapse of legitimacy in one great power would provoke a new war, as had happened in France. The stability of the system thus depended upon the internal stability of its major states, and this domestic security could be ensured by attention to the security of the society of states generally. The one reinforced the other. Metternich and his allies in Berlin and St. Petersburg later attempted to deploy this insight in order to use the Vienna directorate as an engine for domestic repression. Be that as it may, the focus on the domestic constitutional structure of the member states represents a crucial step in the development of a constitution for the society of states.