There is no theoretical idea in the art of war which has played such a part in criticism as that we are now entering upon. It is the “great war steed” in all accounts of battles and campaigns; the most frequent point of view in all arguments, and one of those fragments of scientific form with which critics make a show of learning. And yet the conception embodied in it has never yet been established, nor has it ever been clearly explained.
We shall try to ascertain its real meaning, and then see how far it can be made available for practical use.
We treat of it here because the defence of mountains, river defences, as well as the conceptions of strong and entrenched camps with which it closely connects itself, required to have precedence.
The indefinite confused conception which is concealed behind this ancient military metaphor has sometimes signified the most exposed part of a country at other times the strongest.
If there is any spot without the possession of which no one dare venture to penetrate into an enemy’s country that may, with propriety, be called the key of that country. But this simple, though certainly at the same time also, barren notion has not satisfied theorists, and they have amplified it, and under the term key of a country imagined points which decide upon the possession of the whole country.
When the Russians wanted to advance into the Crimean peninsula, they were obliged to make themselves masters of the isthmus of Perekop and its lines, not so much to gain an entrance generally—for Lascy turned it