David Edgerton argues in Britain's War Machine that Britain had one of the most mechanised armies in 1939 and further mechanised it. An expert in Soviet forces can weigh in on the degree of mechanisation in the Red Army. It should be remembered that armies were changing prior to the war as tension built and then during the war as production was shifted to the war economy. This means the level of mechanisation varied throughout time and of course did so according to place with highly mechanised divisions serving as front line troops. The British example is important as, being a naval power, their military was small and so could have a high proportion of mechanised units without a ruinous cost. Germany as a continental power had many more people to equip and consequently a given level of production expenditure would take longer to achieve a given level of proportionate mechanisation. Further, Germany, in spite of being seen as the only power to have prepared for WW2, was at a disadvantage of having to rebuild a military that was reduced by the Treaty of Versailles while (as Edgerton forcefully argues in the case of Britain) other powers spent the interwar period modernising their existing forces. That Germany went on to invade Russia with more horses than Napoleon should be seen in the context of production needing to be allocated to either expansion or replacement of an existing military and that rapid expansion of requires recruitment from any available source. Finally it is worth pointing out that US production found its way to British and Soviet forces adding to their already considerable productive capacity and the contrast with Germany.