During the period 1797 to 1806, Napoleon Bonaparte emerged as the constitutive force in Prussian politics. His radical hegemonic pretensions shaped Prussian foreign policy; this self-same threat powered the intense executive reform debate before Jena; by 1805–6, his favour could make or break Prussian statesmen in the antechamber of power; and the tide of events he unleashed in 1804 was to have a powerfully solvent effect on policies, politics and structures in the old Prussia.

The impact of Napoleon on Prussian policy was a direct reflection of the geopolitical situation of the monarchy. Their geographical exposure to French power made Prussian statesmen both more sensitive to Napoleonic ambitions and less inclined to oppose them. Unlike Great Britain and Russia, they took a very narrow view of European security. So long as Prussia's immediate sphere of influence in North Germany remained inviolate, she was prepared to permit those French encroachments in western Germany, Italy and elsewhere which she was powerless to stop in any case. This policy of strict neutrality – the ‘middle way’ – was repeatedly and explicitly justified with reference to the ‘imperious dictates’ of geography. But the Prussians were concerned not merely to stay out of any Franco-Russian dispute; they also aimed to mediate a limited rapprochement between the two powers. This would save them from being caught in the inevitable crossfire as French and Russian forces advanced to do battle in northern Germany.