retreat by convoy

assuming a convoying fleet didn’t come under attack in the move phase, and the destination zone was not a contested area, is it possible to retreat by convoy ?
A web version of the classic Diplomacy board game
https://www.playdiplomacy.com/forum/
https://www.playdiplomacy.com/forum/viewtopic.php?f=13&t=62486
sarge57 wrote:assuming a convoying fleet didn’t come under attack in the move phase, and the destination zone was not a contested area, is it possible to retreat by convoy ?
sarge57 wrote:Well thank goodness that rule wasn't in effect at Dunkirk in 1940 ???