This is also incoherent...
If the Chamberlain-headed British government "was intent on giving Hitler a free-hand towards the east," then why did it declare war when Hitler invaded Poland? All it had to do was shrug its shoulders when the panzers moved east, and declare that Britain's security interests on the north European plain stopped at the Rhine.
But the British government did not do that. Instead they declared war and mobilized for a prolonged struggle of attrition...
Brad DeLong