What if Hitler following the fall of France decides that finishing Britain needs to be done before proceeding in the East against Russia? Now, this means either conquest or getting a negotiated surrender / peace. Either will suffice. I think that this is within Germany's ability to actually do. Some initial steps would include: Throwing a larger force into North Africa. This would include sufficent engineers and logistics units to support a larger force there than was historically possible. The Luftwaffe commences a crash program of pilot training to ensure sufficent replacements for an ongoing air war. The Luftwaffe sizes operations against Britain such that they can be sustained for a longer period. The Germans also begin looking at alternatives for the "destruction" of England by various means of bombardment. U-Boat production is ramped up to put more into the Atlantic. If Germany is able to either stall or eliminate the British in North Africa (emminently doable) while increasing the pressure on Britain through their u-boat campaign, the Germans might be able to gain a negoitated peace.