I keep looking at the map below and just wonder if Rundstedt had prepared better on 27th May whether the Wehrmacht could have cut off the bulk of the BEF (and de Laurencie's French Forces) from the Dunkirk beaches. As a reminder, the Halt Order for the Panzers was issued at midday on 24th May - to halt on the Aa Canal - however Reinhardt's 8 Panzer was already across and their Reconnaissance had attacked but been repulsed at Hasebrouck by a very weak unit - woodforce. Guderian was over at Watten and in total 6 good crossings were in German hands. The Halt Order was lifted just after mid day on 26 May but the Panzer forces did not roll until morning of 27th May. And an explanation of the map which shows the situation on morning 27th May - the solid black arrows represent the line of retreat taken by I Corp and the dotted arrows II Corp - however on 27th May II Corp was South of Ypres - so please, for the propose of my question ignore this and the circled dots around 3Div and 112L further north. So what happened? Please look at map - running from north to south along the line of the Panzer divisions, I have indicated (in brown) the distance achieved by the Panzers before they were withdrawn on the morning of 29th May. The yellow line is the direction they probably would have taken if more successful or had more time. The French have a pretty solid line in front of 1 Panzer and benefit from numerous channels which assist strong defence. South at Watten only part of 2 Panzer was available since the remainder is still at Boulogne. There is open, flat country with no canals and only one British Brigade is in front of their initial objective Wormhout. Reinhardt's 6 Panzer is required to invest Cassel, low but dominating Hill (one of three low hills - the others are more or less in a line running East, Mont Des Cats and Kemmel) 8 Panzer is well ensconced over the canal at both St Omer and Aire - faced by one Brigade and a depleted Division (44). The stated route is Hasebrouck , Mont des Cats to Kemmel. Then the are no less than four Panzer Divisions - 3, 4 5 and 7 Panzer in the small area from La Bassee to Estaires - these are successful in driving North East and forming a pocket around the French 1st Army. The British Divisions on the Belgian border from Ypres to Roubaix, 1, 3, 4, 5 and 50 all slip away from this advance. So it seems to me that if Rundstedt had used the "dead time" on 25 and 26th May to prepare a Schwerpunkt at St Omer\Aire (with 8 Panzer) or at Watten by re-assigning some of the Panzers (ie 3, 4, 5 and 7 Panzer) from La Basse, then there is every chance that an encirclement by joining Army Group B at Ypres could have netted the BEF as well as the French 1st Army.