Jomini on the Nature of War – Part V – Lines of Operation

This post continues the series of “Jomini on the Nature of War.” Part I: Introduction is available here, Part II: The Burgeoning Military Theorist here, Part III: The Founder of Modern Strategy here, and Part IV: The Basics here.

“Principles were guides to action, not infallible mathematical calculations. The specific application of principles would vary with the thousand changing physical and psychological factors that made war ‘a great drama.’ Genius would defeat the military pendant, just as talent and experience would outdo the bumbling novice. But the principles themselves, whose truth is demonstrated by all military experience, could not be ignored without peril and, when followed, had ‘almost invariably’ (Presque en tout temps) brought victory.”[i]

 Jomini’s arguments for “immutable ‘principle’ of war” rested on the concept of “lines of operation” by which he meant…

• “where an armed force fights,
• for what objective, and
• in what force relative to the total available military power of the state.”[ii]

He identified two types of lines of operation, those that are:

• Natural:
  • rivers,
  • mountains,
  • seacoasts,
  • oceans,
  • deserts, and
  • sheer distance through, over, and around which military operations must be conducted.”[iii]
  • Also included in this category are man-made, permanent structures that constrict the conduct of warfare including: fortifications, military bases, political boundaries and road networks.[iv]
• Concerned exclusively with strategic choice about:
  • where to fight,
  • to what purpose,
  • in what force, etc.[v]

[i - v] John Shy, “Jomini,” in Makers of Modern Strategy from Machiavelli to the Nuclear Age, ed. Peter Paret (Princeton: Princeton University Press, 1986), 154, 166.

Photo: Union entrenchments near Kenesaw Mountain, Ga., 1864. 111-B-531. The National Archives.

Map: First Manasas