The fourth principle, the "Assistance of the Theatre of War", is naturally an advantage on the side of the defensive. [...] the army on the defensive continues to keep up its connection with everything, that is, it enjoys the support of its fortresses, is not weakened in any way, and is near to its sources of supply. [...] The campaign of 1812, gives as it were in a magnifying glass a very clear illustration of the effect of the means specified under principles 3 and 4. [...] It is true that with the exception of Sweden there is no country in Europe which is situated like Russia, but the efficient principle is always the same, the only distinction being in the greater or less degree of its strength.