Offense/Defense Dominance

Factors Shaping the Offense/Defense Balance

The offense/defense balance is shaped by military, geographic, and domestic social and political factors, as well as by international institutions such as alliances.

Military technology, doctrine, and force posture can favor the offense or the defense. For example, the coming of nuclear weapons strongly favored the defense. Any state with a secure nuclear deterrent is secure from conquest, as it can annihilate any attacker. And a secure deterrent is far easier to maintain than to threaten, so nuclear powers can defend themselves against states with many times their economic power—as they often could not before nuclear weapons appeared. Hence the nuclear revolution is a defensive revolution in warfare.

Guerrilla war is a defensive form of war, because it is useful for defending territory but not for aggression. Hence the development of guerrilla doctrine and the spread of small arms (which enable guerrilla tactics) in the 20th century moved the global offense/defense balance toward the defense.

The development of the machine gun, rapid fire rifles, barbed wire, and railroads (which enhanced [Page 458]the mobility of defenders but not attackers) favored the defense in Western Europe in 1914–1918. On the other hand, the development of tanks, combined with Germany's invention of a new offensive armored doctrine—blitzkrieg—moved the offense/defense balance in Europe back toward the offense in the late 1930s.

Geographic barriers such as mountains, rivers, or oceans favor the defense by impeding the movement of attackers. Conquest among island states is hard because water barriers protect them from one another. Conquest among states that lie exposed on an open plain is easier. Densely forested terrain favors the defense by supporting guerrilla resistance against invaders.

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