The executive council, directed, as to military operations by general Servan, advanced the newly-levied battalions towards the frontier. As a man of judgment, he was desirous of placing a general at the threatened point; but the choice was difficult. Among the generals who had declared in favour of the late political events, Kellermann seemed only adapted for a subordinate command, and the authorities had therefore merely placed him in the room of the vacillative and incompetent Luckner. Custine was but little skilled in his art; he was fit for any dashing _coup de main_, but not for the conduct of a great army intrusted with the destiny of France. The same military inferiority was chargeable upon Biron, Labourdonnaie, and the rest, who were therefore left at their old stations, with the corps under their command. Dumouriez alone remained, against whom the Girondists still retained some rancour, and in whom they, moreover, suspected the ambitious views, the tastes, and character of an adventurer, while they rendered justice to his superior talents. However, as he was the only general equal to so important a position, the executive council gave him the command of the army of the Moselle.
Dumouriez repaired in all haste from the camp at Maulde to that of Sedan. He assembled a council of war, in which the general opinion was in favour of retiring towards Châlons or Rheims, and covering themselves with the Marne. Far from adopting this dangerous plan, which would have discouraged the troops, given up Lorraine, Trois Evêchés, and a part of Champagne, and thrown open the road to Paris, Dumouriez conceived a project full of genius. He saw that it was necessary, by a daring march, to advance on the forest of Argonne, where he might infallibly stop the enemy. This forest had four issues; that of the Chêne-Populeux on the left; those of the Croix-au-Bois and of Grandpré in the centre, and that of Les Islettes on the right, which opened or closed the passage into France. The Prussians were only six leagues from the forest, and Dumouriez had twelve to pass over, and his design of occupying it to conceal, if he hoped for success. He executed his project skilfully and boldly. General Dillon, advancing on the Islettes, took possession of them with seven thousand men; he himself reached Grandpré, and there established a camp of thirteen thousand men. The Croix-au-Bois, and the Chêne-Populeux were in like manner occupied and defended by some troops. It was here that he wrote to the minister of war, Servan:--"Verdun is taken; I await the Prussians. The camps of Grandpré and Les Islettes are the Thermopylae of France; but I shall be more fortunate than Leonidas."