Napoleon had calculated that Kutuzov, expecting reinforcements from Russia to defend its political allies, would withdraw toward Vienna; he envisioned that his and Kutuzov's armies would engage in a great battle at Vienna, and that this battle would decide the war.
This failure was an important factor when Mortier lost his corps' so-called "eyes": after he and Gazan had crossed the Danube, the French dragoons had veered to the northwest, leaving only three squadrons of the 4th Dragoons available for reconnaissance.