Alternate Psychology

  I think it might be to simplify things and also in reaction to the argument that in an ISOT going back more than a couple of centuries from the present age the down-timers reaction would be along the line of "burn the heretics".  Can recall when I was on the AH site that posters often argued that people in earlier times were far more sophisticated than many nowadays assumed.

   I think if the bulk of the BEF was lost in France and Britain still decided to fight on then you would still get the Battle of Britain with almost certainly the same result.  Its possibly that the RAF might be forced to withdraw northwards, outside of Luftwaffe fighter range but that would give them a chance to regroup.  This might prompt the Germans to invade but its likely to end in disaster for them given a revived RAF against an overstretched LW and with the RN as well. 

  As 575 said that's likely to largely be infantry and para losses along with air and naval/merchant shipping units so a Barbarossa in 41 would still be quite possible and probably not greatly weakened but might also mean Germany doesn't rescue Italy in both the Balkans and N Africa.  I agree it would hit German prestige markedly although there is a possible down side of this as it might make Stalin too complacent - albeit he seems to have been overwhelmingly so anyway until the invasion struck.

  A concentration on a Med campaign could be dangerous for Britain, especially if Franco and Vichy could be strong-armed into allowing passage and use of their bases in Spain and FNA.  That would ensure the loss of Gibraltar and Malta and bases in Spain and possibly French Morocco considerably increasing the threat to British supply lines.  However if the British leadership is responsible I think Egypt would be safe as the logistical burden facing the Axis to project power across the Med and then across the desert from Tripoli to Alexandria.  [They can use ports further east such as Benghazi and Tobruk but those are also a fair distance from the front and of limited capacity and would require more consumption of fairly scarce fuel oil for the ships involved].  Also Britain has counters to this strategy in terms of occupying the Canary Is in the event of Spain joining the Axis while such forcing of Vichy's hands is likely to mean more French colonies defect to the Free French quicker.

  An invasion through Turkey is possible but the Turks are likely to put up fierce resistance and the terrain and logistics are very bad, especially in eastern Turkey.  Its possible but then they would have to project power into the Levant area where Britain would have much shorted and more capable supply lines as their likely to occupy Vichy Syria.  Also its unlikely to give a clear victory in time to make Barbarossa practical in 1941.  Plus I don't expect Stalin would welcome such a German action as it would mean they gain control of the Turkish straits and advancing further eastward poses a threat to Baku and its vital oil.  This could prompt a Soviet intervention which could threaten the flank of any German attack into say Syria.