Arguing that frontal assault was bound to fail at great cost in lives, as proven in World War I, he recommended the "indirect approach" and reliance on fast-moving armoured formations.

His pre-war publications are known to have influenced German World War II strategy, though he was accused of prompting captured generals to exaggerate his part in the development of blitzkrieg tactics.

He also helped promote the Rommel myth and the "clean Wehrmacht" argument for political purposes, when the Cold War necessitated the recruitment of a new West German army.

On the outbreak of World War I in August 1914, Liddell Hart volunteered for the British Army, where he became an officer in the King's Own Yorkshire Light Infantry in December[6] and served with the regiment on the Western Front.

In it, Liddell Hart strove to instil the lessons of 1918, and carried on a correspondence with Maxse, a commanding officer during the battles of Hamel and Amiens.

In the mid-to-late 1920s Liddell Hart wrote a series of histories of major military figures through which he advanced his ideas that the frontal assault was a strategy bound to fail at great cost in lives.

He claimed that historically, "the British way in warfare" was to leave Continental land battles to her allies, intervening only through naval power, with the army fighting the enemy away from its principal front in a "limited liability" commitment.

Liddell Hart foresaw the need for a combined arms force with mobile infantry and artillery, which was similar but not identical to the make-up of the panzer divisions that Heinz Guderian developed in Germany.

[15][16] The ideas influenced Neville Chamberlain, then Chancellor of the Exchequer, who argued in discussions of the Defence Policy and Requirements Committee for a strong air force, rather than a large army that would fight on the Continent.

[32] [N]ot of one period but of its whole course, points to the fact that, in all decisive campaigns, the dislocation of the enemy's psychological and physical balance has been the vital prelude to his overthrow.Liddell Hart was an advocate of the notion that it is easier to succeed in war by an indirect approach.

[37] Even more impressive in Liddell Hart's eyes was the further campaign by Epaminondas, his invasion of the Peloponnese, in which in winter and in separate columns, he invaded Spartan controlled territory.

When he visited Israel in 1960 his trip stimulated more public interest than that of any other foreign visitor except Marilyn Monroe.Liddell Hart's reputation as a military thinker stood very high at his death in 1970.

Post-mortem assessments, however, have been more ambivalent.At the height of his popularity, John F. Kennedy called Liddell Hart "the Captain who teaches Generals" and was using his writings to attack the Eisenhower administration, which he said was too dependent on nuclear arms.

[46] Retired Pakistani General Shaafat Shah called Liddell Hart's book Strategy: the Indirect Approach "A seminal work of military history and theory".

[47] In the book Science, Strategy and War, Frans Osinga mentioned while the Dutchman spoke of John Boyd, "In his recently published study of modern strategic theory, Colin Gray ranked Boyd among the outstanding general theorists of the strategy of the 20th century, along with the likes of Bernard Brodie, Edward Luttwak, Basil Liddell Hart and John Wylie".

[49] Following the Second World War Liddell Hart pointed out that the German Wehrmacht adopted theories developed from those of J. F. C. Fuller and from his own, and that it used them against the Allies in Blitzkrieg warfare.

[50] Some scholars, such as the political scientist John Mearsheimer, have questioned the extent of the influence which the British officers, and in particular Liddell Hart, had in the development of the method of war practised by the Panzerwaffe in 1939–1941.

Following these interviews, many of the generals said that Liddell Hart had been an influence on their strategies, something that had not been claimed previously nor has any contemporary, pre-war, documentation been found to support their assertions.

"[52] Naveh stated that, by manipulation and contrivance, Liddell Hart distorted the actual circumstances of the Blitzkrieg formation and obscured its origins.

[53]Naveh stated that in his letters to German generals Erich von Manstein and Guderian, as well as to relatives and associates of Rommel, Liddell Hart "imposed his own fabricated version of Blitzkrieg on the latter and compelled him to proclaim it as original formula".

One example of the influence of these men on Guderian was the report on the Battle of Cambrai published by Fuller in 1920, who at the time served as a staff officer at the Royal Tank Corps.

Luvass saw Liddell Hart as a scholar who needed public recognition and influence, but also a naturally generous person whose efforts in building a connection to other people should not be assigned motives without evidence.

According to Forbes, Mearsheimer relies less on the actual text than on Frank Mahin's review, to make the claim that Hart fills the book with fabricated comments by Germans to exaggerate his role.

The myth was initially fueled by Nazi propagandists, with Rommel's participation, as a means of praising the Wehrmacht and instilling optimism in the German public.

Starting in 1941, it was picked up by the British press and disseminated in the West as an element of explaining Britain's continued inability to defeat the Axis forces in the North Africa campaign.

His reputation for conducting a clean war was used to support West German rearmament and reconciliation between the former enemies – Britain and the United States on one side and the new Federal Republic on the other.

Additions to the chapter published in 1951 concluded with laudatory comments about Rommel's "gifts and performance" that "qualified him for a place in the role of the 'Great Captains' of history".

[51] According to Connelly, Young and Liddell Hart laid the foundation for the Anglo-American myth, which consisted of three themes: Rommel's ambivalence towards Nazism; his military genius; and the emphasis of the chivalrous nature of the fighting in North Africa.

Liddell Hart had prepared a treatise titled Some Reflections on the Problems of Invading the Continent which he circulated amongst political and military figures.

MI5 suspected that Liddell Hart had received plans of the invasion from General Sir Alfred "Tim" Pile who was in command of Britain's anti-aircraft defences.