After arriving in Casablanca, "Jean Bart" had most of her anti-aircraft guns removed to strengthen the defenses of the port: the 90 mm and 37 mm guns were moved to the jetties protecting the harbor and two of the six 13.2 mm guns were put on trucks. Following their defeat in the Battle of France, the French signed the Armistice of 22 June 1940, ending their participation in the conflict. During the peace negotiations, the French proposed neutralizing "Jean Bart" and several other ships in Oran, French Algeria, but they ultimately agreed to take "Jean Bart" and "Richelieu" to Toulon to be demobilized. The Germans later decided against permitting the move, as they feared the British would try to seize the ship during the passage through the Strait of Gibraltar; the British, meanwhile, were under the mistaken impression that the Germans sought to seize the French fleet for their own use. This led to Operation Catapult, a series of attacks on French warships to neutralize vessels that would not defect to the Free French.