the French say 'Japan Airlines' - they do not translate that in French.
The French word for japan is Japon. (styled Le Japon)
japon
Because Japan invaded French Indochina
In French it is "Le Japon" (masculine)
Japanese speak Japanese, I suppose a couple might have learnt french but it is not their main language.
No one wants to be conquered.
japan
In an effort to cut off military supplies to China, Japan invaded French Indochina in 1940. After days of combat, the French Vichy government reached an agreement with Japan that allowed them to occupy Tonkin Bay. The Japanese military had a continued presence in Indochina throughout the war.
When the Japanese ventured into French Indochina in 1940, the US halted several major exports to Japan. Then in 1941 when France fell to Germany and the Japanese took over French Indochina, the US stopped all oil exports to Japan.
'fabriqué au Japon'
Roosevelt cut off the oil supply to Japan and this led to the attack on Pearl Harbor.