Napoleon's first suggestion for a rapid condensation of the French cordon, and an irresistible blow on the centre of the Allies by Tenda-Coni,[7] came to nothing owing to the waste of time in negotiations between the generals and the distant Committee, and meanwhile new factors came into play. The capture of the pass of Argentera by the right wing of the Army of the Alps suggested that the main effort should be made against the barrier fortress of Demonte, but here again Napoleon proposed a concentration of effort on the primary and economy of force in the secondary objective. About the same time, in a memoir on the war in general, he laid down his most celebrated maxim: "The principles of war are the same as those of a siege. Fire must be concentrated on one point, and as soon as the breach is made, the equilibrium is broken and the rest is nothing." In the domain of tactics he was and remains the principal exponent of the art of breaking the equilibrium, and already he imagined the solution of problems of policy and strategy on the same lines. "Austria is the great enemy; Austria crushed, Germany, Spain, Italy fall of themselves. We must not disperse, but concentrate our attack." Napoleon argued that Austria could be effectively wounded by an offensive against Piedmont, and even more effectively by an ulterior advance from Italian soil into Germany. In pursuance of the single aim he asked for the appointment of a single commander-in-chief to hold sway from Bayonne to the Lake of Geneva, and for the rejection of all schemes for "revolutionizing" Italy till after the defeat of the arch-enemy. Operations, however, did not after all take either of these forms. The younger Robespierre perished with his brother in the _coup d'etat_ of 9th Thermidor, the advance was suspended, and Bonaparte, amongst other leading spirits of the Army of Italy, was arrested and imprisoned. Profiting by this moment, Austria increased her auxiliary corps. An Austrian general took command of the whole of the allied forces, and pronounced a threat from the region of Cairo (where the Austrians took their place on the left wing of the combined army) towards the Riviera. The French, still dependent on Genoa for supplies, had to take the offensive at once to save themselves from starvation, and the result was the expedition of Dego, planned chiefly by Napoleon, who had been released from prison and was at headquarters, though unemployed. The movement began on the 17th of September; and although the Austrian general Colloredo repulsed an attack at Dego (Sept. 21) he retreated to Acqui, and the incipient offensive of the Allies ended abruptly.