Almost all that we have to say on this subject consists in an
explanation of the term. We find the expression very frequently used by
modern authors and also that they pretend to denote by it something
particular. _Guerre d’invasion_ occurs perpetually in French authors.
They use it as a term for every attack which enters deep into the
enemy’s country, and perhaps sometimes mean to apply it as the
antithesis to methodical attack, that is, one which only nibbles at the
frontier. But this is a very unphilosophical confusion of language.
Whether an attack is to be confined to the frontier or to be carried
into the heart of the country, whether it shall make the seizure of the
enemy’s strong places the chief object, or seek out the core of the
enemy’s power, and pursue it unremittingly, is the result of
circumstances, and not dependent on a system. In some cases, to push
forward may be more methodical, and at the same time more prudent than
to tarry on the frontier, but in most cases it is nothing else than
just the fortunate result of a vigorous _attack_, and consequently does
not differ from it in any respect.