In his work on the Vienna congress, Kissinger seems a little confused in his treatment of Metternich's two communications of 22 October 1814, addressed respectively to Hardenberg and to Castlereagh, and in which the Austrian minister reluctantly offered to be complaisant over Saxony if Prussia helped to check Russia.
In analysing the note to Castlereagh, Kissinger writes that the British minister in his eagerness to secure Metternich's support ‘ignored an enigmatic reservation: that Prussia's annexation of Saxony should not lead to a “disproportionate aggrandizement”, a condition clearly impossible of fulfilment if Prussia first regained her Polish provinces.’1 In fact, the expression ‘disproportionate aggrandizement’, which looks like a quote, is Kissinger's own—it is not found in Metternich's text. In that document, the passage that Kissinger clearly has in mind—the only possible one—stipulates, as a condition for Austria's consent to the annexation of Saxony,
que ce sacrifice serve à la reconstruction de la Prusse et à la consolidation de sa force, mais qu'il ne soit pas une compensation pour son acquiescement à des vues d'aggrandissement, à des opérations politiques aussi dangereuses pour les deux états que contraires à la lettre des traités.
[that this sacrifice contribute to the reconstruction of Prussia and to the consolidation of its strength, but that it must not serve as a reward for its [Prussia's!] acquiescence in designs of aggrandizement, to political operations which are as dangerous for the two states [Prussia and Austria!] as they are contrary to the letter of the treaties.]2
In other words, Metternich is actually referring here to the necessity to prevent the disproportionate aggrandizement of Russia. This is just a restating of the basic message of the whole note—that Prussia should only obtain Saxony if it put up opposition to the expansionist designs of Russia. The reference to ‘dangerous political operations’ is an allusion to Russia's exploitation of Polish nationalism. Read correctly, then, this is not a reservation at all, let alone enigmatic—it is Kissinger who overlooked something here, not Castlereagh.
Kissinger then goes on to analyse the note to Hardenberg, claiming (p.335) that ‘his eagerness to obtain Saxony blinded Hardenberg and caused him to overlook still another subtle reservation, that Metternich's offer was conditional not on the fact of resistance in Poland but on its success.’3 This is unfair on Hardenberg. He could not overlook what Metternich, in his note, does not say. In fact, the note to Hardenberg says very little on Poland and Russia, while holding forth at length on the unfavourable and unsettling impression that the absorption by Prussia of the whole of Saxony would make on the other German powers. Metternich exhorts Prussia urgently to be content with just some Saxon territory. Failing this, Austria's acquiescence in the annexation is explicitly made dependent on the acceptance by Prussia of Austria's strategic desiderata in Germany, in particular the non-acquisition by Prussia of the fortress of Mainz. This is indeed declared a sine qua non, but not the success of the stance to be taken against Russia.4
Kissinger appears to have mixed up the two notes. It is the final paragraph of the one addressed to Castlereagh, and that alone, that may, if one so chooses, be construed as Metternich making his offer dependent on the actual thwarting of Russia's Polish designs:
Je suis chargé…de vous inviter, Mylord, à vous joindre à moi et à faire usage de toute votre influence pour engager les cours de Russie et de Prusse à consentir à des arrangements aussi équitables que nécessaires pour le repos de l'Europe, et que l'empereur [d'Autriche] regarde comme conditions expresses de son consentement, sans lesquelles il ne peut se croire aucunement lié.
[I have orders…to invite you, My Lord, to join me in using all your influence to induce the Russian and Prussian courts to consent to arrangements which are as equitable as they are necessary for the repose of Europe. The emperor [of Austria] regards them as explicit conditions for his consent, and without them he cannot consider himself bound in any way.]5
The ‘arrangements’ to which the text alludes are not, in fact, specified in the note to a degree that would have made it possible to say with any certitude whether or not they had been implemented successfully. All that the note really says, in very general language, is that, in deciding the Polish–Saxon issue, the balance of power should be preserved both in Germany and in Europe, and that Saxony should be sacrificed only as a last resort. Besides, too much should not be read into this in any case. The whole scheme was Castlereagh's idea, and Metternich was making a point of supporting it only reluctantly. It is natural, therefore, that he should have insisted, with Castlereagh, that the scheme had better work, too. If Metternich had seriously intended to make this a sine qua non in a quasi-legal sense, he should have put this condition, preferably in a (p.336) much more precise formulation, to Hardenberg (which is perhaps why Kissinger—wrongly—remembered him as having done so).
Kissinger may have drawn on Webster, who also speaks of Metternich's ‘grudging assent on the Saxon point, on the explicit [sic] understanding that Poland was saved and Mainz was kept out of Prussian influence.’6 The footnote to this refers to Metternich's note to Hardenberg—wrongly, since, as we have seen, that note does not contain the ‘explicit’ understanding that Webster claims. An understanding concerning Poland is only adumbrated in this note. It only says that the Emperor of Austria ‘counts on [compte sur]’ Prussian ‘support [appui]’, as well as ‘absolute conformity of the line taken by the two courts on the Polish issue’. That is all.7 Moreover, Webster's formulation ‘that Poland was saved’ seems rather ill-chosen, given that it was the partition of Poland that was to be saved.