Translate the following English sentence to French:
"If this does not happen, flags of convenience, euphemistically known as 'non-Contracting Parties' , will benefit, not to mention the piracy which lies behind the euphemism, 'stateless vessels' ."
Dans le cas contraire, on favoriserait les pavillons de complaisance dissimulés sous l' euphémisme de "parties non contractantes", voire la piraterie, masquée sous l' euphémisme de "navires apatrides".