The book opens with a comprehensive examination of statesmanship in its relation to war, addressing the political motivations that lead governments into armed conflict. It explores the complexities of offensive and defensive wars, wars of intervention, opinion, and the hazards of undertaking multiple conflicts simultaneously. The author emphasizes that while political and moral factors vary, the military science rests upon immutable principles that must not be violated.
The text then transitions into military policy, exploring statistics, geography, and the institutional foundations of a strong military. It establishes that a successful army requires rigorous recruitment, sound organization, discipline, superior armament, and an effective general staff. Particular attention is given to the selection of commanders and the dangers of relying on councils of war during critical operations.
The core of the work is dedicated to strategy, defining it as the art of making war upon a map. Jomini formulates the fundamental principle of war: throwing the mass of an army successively upon the decisive points of a theater of operations and upon the enemy's communications. He analyzes theater selections, bases of operations, strategic fronts, lines of defense, and zones of operations.
Historical examples from the wars of the French Revolution are scrutinized to illustrate both brilliant successes and catastrophic failures resulting from the choice of operational lines. The text contrasts simple and interior lines against exterior and double lines, demonstrating how proper geographic and strategic direction secures victory.
The final sections address the tactical and logistical elements required to execute strategic plans. This includes the management of marches, the establishment of supply depots, the strategic role of fortresses, intrenched camps, and têtes de ponts. The author concludes with an evaluation of mountain warfare and the unique operational challenges it presents to commanders.
