In mid-1942, in the R1 Region, the three major Gaullist movements (Combat, Libération-sud and the Franc-Tireurs) wanted to coordinate the military units at their disposal to make them more effective.

[clarification needed] On 27 November 1942, in Collonges-au-Mont-d'Or, the constituent meeting of the Southern Zone Coordination Committee was held and the head of the Secret Army was presented by Jean Moulin.

In December, Delestraint, inexperienced in the constraints of illegal life, crossed the demarcation line to make contact with the major movements in the northern zone: Liberation, the Civil and Military Organization (CMO) National, Libération-Nord.

Then, back in the free zone, he took part in the creation of the United Movements of the Resistance (MUR) on 26 January 1943 in Miribel, in Ain.

On 1 February in Lyon's Place du Pont, he arrested Billon, head of the AS in R1 (eleven departments), along with his deputy Pierre Lavergne.

On 3 February, at 31 rue Basse-des-Rives in Saint-Étienne, during a secret meeting of the headquarters of the departmental AS, he also arrested the head of AS Loire, Lieutenant Vidiani, and his companions.

On 27 May 1943, these three arrests, orchestrated by Geissler, featured prominently at the beginning of the Ernst Kaltenbrunner's report addressed to Joachim von Ribbentrop, Minister of Foreign Affairs for the Reich.

In London in February 1943 to meet Allied authorities, Delestraint was asked to make his troop the "nucleus of the future French army", estimated at 150,000 men.