He would not re-create the great kingdom of Poland: he would merely carve out from Prussia the greater part of her Polish possessions.
These two important questions being settled, it only remained for the Czar to plead for the King of Prussia, to acknowledge Napoleon's domination as Emperor of the West, while he himself, as autocrat of the East, secured a better western boundary for Russia.

At first he strove to gain for Frederick William the restoration of several of his lands west of the Elbe.

This championship was not wholly disinterested; for it is now known that the Czar had set his heart on a great part of Prussian Poland.
In truth, he was a sufficiently good disciple of the French revolutionists to plead very cogently his claims to a "natural frontier." He disliked a "dry frontier": he must have a riverine boundary: in fact, he claimed the banks of the Lower Niemen, and, further south, the course of the rivers Wavre, Narew and Bug.

To this claim he had perhaps been encouraged by some alluring words of Napoleon that thenceforth the Vistula must be the boundary of their empires.

But his ally was now determined to keep Russia away from the old Polish capital; and in strangely prophetic words he pointed out that the Czar's claims would bring the Russian eagles within sight of Warsaw, which would be too clear a sign that that city was destined to pass under the Russian rule.[147] Divining also that Alexander's plea for the restoration by France of some of Prussia's western lands was linked with a plan which would give Russia some of her eastern districts,[148] Napoleon resolved to press hard on Prussia from the west.