The prolonged retreat into Moravia, the unexpected feebleness of the
Hapsburg arms, and the lack of supplies weighed heavily on Alexander's
spirits, as is shown in his letter from Olmütz to the King of Prussia
on November 19th: "Our position is more than critical: we stand almost
alone against the French, who are close on our heels. As for the
Austrian army, it does not exist.... If your armies advance, the whole
position will alter at once."[38] A few days later, however, when
27,000 more Russians were at hand, including his Imperial Guard, the
Czar passed from the depths of depression to the heights of
confidence. The caution of his wary commander, Kutusoff, who urged a
Fabian policy of delay and retreat, now began to weary him. To retire
into northern Hungary seemed ignominious. And though Frederick William
held to his resolve of not drawing the sword before December 15th, and
by that time the Archduke Charles with a large army was expected below
Vienna, yet the susceptible young autocrat spurned the behests of
irksome prudence. In vain did Kutusoff and Schwarzenberg urge the need
of delay and retreat: Alexander gave more heed to the rash counsels of
his younger officers. An advance was ordered on Brünn, and a
successful cavalry skirmish at Wischau confirmed the Czar in his
change from the strategy of Fabius to that of Varro.

Napoleon, who was now at Brünn, had already divined this change in the
temper of his foe, and called back his men with the express purpose of
humouring Alexander's latest mood and tempting him on to a decisive
battle. He saw clearly the advantage of fighting at once. The renewed
offers of an armistice, which he received from the prudent Francis,
might alone have convinced him of this; and they came in time to give
him an argument, telling enough to daunt the Prussian envoy, who was
now drawing near to his headquarters.