He was responsible for the idea of distinguishing his fleet from that of Vichy France by adopting the Cross of Lorraine, which later became the emblem of all of the Free French.

He ran unsuccessfully in the legislative elections of 1946 as vice-president of the Rally of Republican Lefts (Rassemblement des gauches républicaines) and then entered private life as a consulting engineer before his retirement in 1960.

In 1933, Muselier, by then promoted to rear-admiral, became Major-General of the port of Sidi-Abdalah in Tunisia, where he wrote social commentaries such as "La Mie de Pain" ("the breadcrumb").

[2] While under the overall command of Canadian Admiral Leonard W. Murray, but acting under the orders of General de Gaulle, Muselier led the liberation of Saint-Pierre and Miquelon on 24 December 1941, unloading three French corvettes and the submarine cruiser Surcouf from Halifax and installing the enseigne de vaisseau Alain Savary as Commissaire of Free France, which angered Roosevelt.

The incident caused tension in relations with Canada and the UK, and eventually led the admiral to resign from his post of Commissaire.

Preferring to work under General Henri Giraud, he served as the temporary civil and military person in charge for Algiers in June 1943 and even appeared to act as the head of an anti-Gaullist putsch,[citation needed] before de Gaulle became head of the French Committee of National Liberation (Comité français de la Libération nationale) on 3 June.