And if the Russians ventured across the Niemen, or the Vistula, as Napoleon at first believed they would,[256] his task would doubtless have been as easy as it proved at Friedland.

Many Prussian officers, so Mueffling asserts, believed that this was the aim of French diplomacy in the early autumn of 1811, and that the best reply was an unconditional surrender.

On the other hand, there is the fact that St.Marsan, Napoleon's ambassador at Berlin, assured that Government, on October 29th, that his master did not wish to destroy Prussia, but laid much stress on the supplies which she could furnish him--a support that would enable the Grand Army to advance on the Niemen _like a rushing stream_.
The metaphor was strangely imprudent.

It almost invited Prussia to open wide her sluices and let the flood foam away on to the sandy wastes of Lithuania; and we may fancy that the more discerning minds at Berlin now saw the advantage of a policy which would entice the French into the wastes of Muscovy.

It is strange that Napoleon's Syrian adage, "Never make war against a desert," did not now recur to his mind.