When the Congress Poland was created, its king happened to be the tsar of Russia, so there was no danger of Kingdom of Poland trying to claim its former lands.
Actually, this practically happened because Alexander was quite willing to listen to these ideas until he faced a strong Russian opposition. The problem was that on one side the Polish political leaders understandably wanted their former lands back (*) and on another the Russians, also understandably, did not see any reason why should give away a considerable part of the Russian Empire even if it was just the same for their emperor. Alexander, also understandably, chose the safe option: climate of the St-Petersburg area was notoriously unhealthy causing deadly cases of the hemorrhoids, heart strokes and, if push comes to shove, probably even sneezing could end up badly. 😂
In this scenario
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(*) Which meant Lithuania, Belorussia and perhaps even the right bank Ukraine.
But I agree that Russia might not be happy about strong Poland on its border. OTOH they can not do much about it, except fighting Napoleon who just crushed Prussia and Austria (again). The tsar might settle with a part of Eastern Galicia, possibly East Prussia (just to keep it away from Poland) and some guarantee that Poland renounces any claim to territories that are now Russian.
Well, in OTL Nappy adopted pretty much “bite me” attitude because soon after Tilsit his relations with Alexander started getting sour. The issue of a guarantee was raised but instead of guaranteeing that expansion of the DoW is not going to happen (as Alexander required) Napoleon promised that he is not going to help to extend the Duchy. In a meantime Davout kept building up the Duchy’s army (by some estimates it reached 100,000).
In this TL we have a different set of the circumstances and attitudes. Russia is a reliable and
very important ally which is faithfully maintains the alt-CS system (profiting from it, to be sure). Change from this course, even without a war, could be a serious economic blow to Napoleon. It is probably reasonable to assume that prior the the beginning of war not just the coalition members but Napoleon as well had some diplomatic exchange with Constantine and it is reasonable to assume that some promises and guarantees are given regarding this very touchy issue to keep Russia friendly or at least neutral because, with all his dislike of a war, Constantine potentially may be tempted to join coalition (volatility of his character is a serious factor).
OTOH, unlike Russia, DoW does not not have space for a maneuver: either Napoleon wins or the Duchy ceases to exist. And if it’s cooperation can be taken for granted, Napoleon does not really have award the loyalty (just as he did not in OTL). The Duchy may or may not get something after the victory but only as long as it does not hurt Napoleon’s greater interests.
Now, as far as the rewards are involved, Prussia is somewhat of a part of the Russian “sphere of influence” even if it is trying to become an independent player by joining the 5th coalition. Both Nappy and Constantine (who, unlike Alexander, is not obsessed with the idea of being protector of Prussia) may consider that Prussia should be punished for its bad behavior but Russia is still interested in having it as some kind of a semi-vassal and rather a friendly one.
Not annexing East Prussia an
not allowing Napoleon to give it to the Duchy is important to achieve that goal exactly because of its geographic location.
Nappy may decide to take Silesia from Prussia but he does not have to give it to the Duchy because he can give it to Saxony. The fact that the King of Saxony is also a head of the Duchy is just a happy coincidence and the important part is that the Duchy is not excessively strengthened by adding a region with the strong economy.
Taking Galicia from Austria is another story. Unlike Prussia, Austria is nobody’s satellite and somebody can also refresh Constantine’s memory regarding Suvorov’s Switzerland campaign in which he participated, just to maintain a correct attitude. Of course, giving the Western Galicia to DoW is strengthening it but if this is balanced by giving the Eastern Galicia to Russia, the whole schema starts looking well balanced and should not raise too many hackles.
The part about the renounced claims is interesting but pretty much meaningless. The only important document would be Napoleon’s formal obligation not to allow any expansion of the Duchy at Russian expense. The Polish “renouncement” can be easily denounced by the “patriots” and would not prevent the unofficial help to the “activists” on the Russian territory.
If Napoleon can appease Russia, he can reward the Poles. While mentioning Walewska was a little joke of mine, I still believe that strong Poland would be a useful French watchdog in Central Europe and potentially the first line of defence against Russia.
Which is exactly why in this TL it’s existence as a strong state may become inconvenient both for Napoleon and Constantine. 😉
Unlike OTL France and Russia are friendly so the defense against Russia (Russia launching an offensive war against France is rather unlikely) is not really important (having a loyal vassal at the Prussian and Austrian backyards is a different issue). OTOH, there is no guarantee that a strong Polish state is not going to get Napoleon involved into a war against Russia: the Poles of that period were not famous for their levelheadedness.
So e.g. Napoleon can promise the tsar that there will be no French troops in Poland. Poles would be too weak to launch an invasion of Russia on their own and they would be told that France will not back them in any attempt to regain their lost territories.
On that we both are in an agreement but the problem would be not an invasion but steering up the trouble in the Russian Polish territories with a potential escalation of the whole thing. For example, there is an uprising in Lithuania helped by the volunteers and weapons from the Duchy. Russian attempts to block the border are resulting in the clashes with the Duchy troops and almost inevitably result in penetration of the Duchy territory (see Balta Incident which triggered Russian-Ottoman War). The Duchy appeals to Napoleon and even in the best case scenario the Russian-French relations may sour.
