How Norway and Crete might shorten the European war

If Norway and Crete had gone differently, could the war in Europe have been much shorter?

Yes; holding both could constrain German supply, submarine access, air operations, and control of the eastern Mediterranean.

Destroying German invasion shipping at sea and holding Norway would restrict Swedish iron-ore supplies and make German submarine access much harder. Retaining Crete would also preserve more British control in the eastern Mediterranean and avoid some historical losses. Arctic convoys would then face a much weaker German air and submarine position without bases in Norway. Interception was plausible if the British task force had been positioned farther south to meet the invasion convoy, although working German torpedoes could have changed the encounter.