information:filtering
Late 20th and early 21st century

The deterrence strategy of the United States in the 1950s was closely inspired by President Dwight Eisenhower 's reading of Clausewitz as a young officer in the 1920s. Eisenhower was greatly impressed by Clausewitz's example of a theoretical, idealized "absolute war" in Vom Kriege as a way of demonstrating how absurd it would be to attempt such a strategy in practice. For Eisenhower, the age of nuclear weapons had made what was for Clausewitz in the early-19th century only a theoretical vision an all too real possibility in the mid-20th century. From Eisenhower's viewpoint, the best deterrent to war was to show the world just how appalling and horrific a nuclear "absolute war" would be if it should ever occur, hence a series of much-publicized nuclear tests in the Pacific, giving first priority in the defense budget to nuclear weapons and to their delivery-systems over conventional weapons, and making repeated statements in public that the United States was able and willing at all times to use nuclear weapons. In this way, through the massive retaliation doctrine and the closely related foreign-policy concept of brinkmanship, Eisenhower hoped to hold out a credible vision of Clausewitzian nuclear "absolute war" in order to deter the Soviet Union and/or China from ever risking a war or even conditions that might lead to a war with the United States.

...Philanthropists may easily imagine there is a skillful method of disarming and overcoming an enemy without causing great bloodshed, and that this is the proper tendency of the art of War. However plausible this may appear, still it is an error which must be extirpated; for in such dangerous things as war, the errors which proceed from a spirit of benevolence are just the worst. As the use of physical power to the utmost extent by no means excludes the co-operation of the intelligence, it follows that he who uses force unsparingly, without reference to the quantity of bloodshed, must obtain a superiority if his adversary does not act likewise. By such means the former dictates the law to the latter, and both proceed to extremities, to which the only limitations are those imposed by the amount of counteracting force on each side.

After 1970, some theorists claimed that nuclear proliferation made Clausewitzian concepts obsolete after the 20th-century period in which they dominated the world. John E. Sheppard, Jr., argues that by developing nuclear weapons, state-based conventional armies simultaneously both perfected their original purpose, to destroy a mirror image of themselves, and made themselves obsolete. No two powers have used nuclear weapons against each other, instead using diplomacy, conventional means, or proxy wars to settle disputes. If such a conflict did occur, presumably both combatants would be annihilated. Heavily influenced by the war in Vietnam and by antipathy to American strategist Henry Kissinger, the American biologist, musician, and game-theorist Anatol Rapoport argued in 1968 that a Clausewitzian view of war was not only obsolete in the age of nuclear weapons, but also highly dangerous as it promoted a "zero-sum paradigm" to international relations and a "dissolution of rationality" amongst decision-makers.

The end of the 20th century and the beginning of the 21st century have seen many instances of state armies attempting to suppress insurgencies and terrorism, and engaging in other forms of asymmetrical warfare. Clausewitz did not focus solely on wars between countries with well-defined armies. The era of the French Revolution and Napoleon was full of revolutions, rebellions, and violence by "non-state actors" - witness the wars in the French Vendée and in Spain. Clausewitz wrote a series of "Lectures on Small War" and studied the rebellion in the Vendée (1793–1796) and the Tyrolean uprising of 1809. In his famous "Bekenntnisdenkschrift" of 1812 he called for a "Spanish war in Germany" and laid out a comprehensive guerrilla strategy to be waged against Napoleon. In On War he included a famous chapter on "The People in Arms".

One prominent critic of Clausewitz is the Israeli military historian Martin van Creveld. In his 1991 book The Transformation of War, Creveld argued that Clausewitz's famous "Trinity" of people, army, and government was an obsolete socio-political construct based on the state, which was rapidly passing from the scene as the key player in war, and that he (Creveld) had constructed a new "non-trinitarian" model for modern warfare. Creveld's work has had great influence. Daniel Moran replied, 'The most egregious misrepresentation of Clausewitz's famous metaphor must be that of Martin van Creveld, who has declared Clausewitz to be an apostle of Trinitarian War, by which he means, incomprehensibly, a war of 'state against state and army against army,' from which the influence of the people is entirely excluded." Christopher Bassford went further, noting that one need only read the paragraph in which Clausewitz defined his Trinity to see

"that the words 'people,' 'army,' and 'government' appear nowhere at all in the list of the Trinity's components.... Creveld's and Keegan's assault on Clausewitz's Trinity is not only a classic 'blow into the air,' i.e., an assault on a position Clausewitz doesn't occupy. It is also a pointless attack on a concept that is quite useful in its own right. In any case, their failure to read the actual wording of the theory they so vociferously attack, and to grasp its deep relevance to the phenomena they describe, is hard to credit."

Some have gone further and suggested that Clausewitz's best-known aphorism, that war is a continuation of policy with other means, is not only irrelevant today but also inapplicable historically. For an opposing view see the sixteen essays presented in Clausewitz in the Twenty-First Century edited by Hew Strachan and Andreas Herberg-Rothe.

In military academies, schools, and universities worldwide, Clausewitz's Vom Kriege is often (usually in translation) mandatory reading.

Some theorists of management look to Clausewitz - just as some look to Sun Tzu - to bolster ideas on the concept of leadership.