“The British Army wasn’t prepared to fight a first-class European army in 1939 for the simple reason that Britain hadn’t prepared itself to do so.”

By Dr. Robert Lyman

THE BRITISH ARMY was catastrophically unprepared for war in 1939. But it wasn’t just the army that was unprepared. Despite a last-minute rush to re-arm, so too was the whole country.

In Britain a deep-seated passivity had set in following the end the Great War. This belied the reality that in Europe, the ending of the war in fact opened the door to unheralded political chaos and instability. This upheaval in time would overcome the forces of stability and lead directly to yet another devastating conflict. In the years immediately following the arrival of peace in 1918, Britain hoped it could close the door on any future European or continent commitment and return to the halcyon days when its only security commitments were the defence of its widely flung Empire.

The weakness at the heart of British planning for war was a direct reflection of Britain’s strategic, political, societal and economic situation during the inter-war period. Britain – both the British public and the country’s various governments – simply wasn’t mentally prepared to go to war again so soon after the trauma of the Great War. As a result, it made no proper preparation for another full-on industrial war against a peer opponent on the continent. This was fundamentally a failure of political and military imagination; the inability to think through what a potential war might look like and to prepare for this possibility accordingly.

There were five primary causes of the decline of British military effectiveness in 1939.

Lack of strategy

In the first place, there was no clear strategic plan for the army. Strategies are determined by having a clear understanding of who a future enemy might be.

Following the end of the Great War, until the late 1930s no one seemed bothered to define this essential point of direction. There was a remarkably inadequate grand strategic conversation (i.e., at a national, governmental level) about the purpose, structure, and nature of the army. There was plenty of talking, but very little of it focused on realistic determination as to who it might have to fight, and how.

This was a problem, because it meant that Britain was unable to determine how to structure its armed forces and the associated cost. Was the focus of the army to be the continent, or the empire, or both? No one knew. As a result, the last known plan reasserted itself – imperial defence, à la 1914. This meant that the army wasn’t structured or equipped to fight a specified enemy in a defined set of circumstances.

Instead, the British Army and its cousin, the Indian Army, was expected to be a generic jack-of-all-trades, without the structure, doctrine, training, or equipment to fight the type of war it had become the master of in 1918.

While there was some doctrine, and considerable doctrinal debate, little was anchored in a clear definition of what a future war was expected to look like. There was no operational design for the British Army derived directly from an analysis of the threat it faced. If one had been established, the BEF would have been thoroughly prepared for the German Blitzkrieg in France and the Low Countries in 1940 or the similar Japanese kirimoni sakusen (“running charge”) in 1941 and 1942.

The British Army wasn’t prepared to fight a first-class European army in 1939 for the simple reason that Britain hadn’t prepared itself to do so. Likewise, when it came to fighting the Japanese in 1941 and 1942 in Malaya and Burma, the British found that not only had it failed to prepare adequately for a potential Japanese invasion of its vulnerable Far Eastern colonies, but that it had no idea as to how to fight the Imperial Japanese Army.

There were two connected failures here. The first was one of strategic preparedness, the blame for which was both governmental and strategic. The second was of training, doctrine and military preparedness by the British Army in Europe and Asia to fight. When they emerged from their assault boats at Kota Bahru on the morning of Dec. 8, 1941, the Japanese could as well have come from Mars given how little the British knew about them and their warfighting methods.

Pacifism and nostalgia

Second, as a country, Britain was unprepared both politically and culturally for another war so soon after the last. In 1919, the country seemed to want to look backward to embrace the days of peace that had preceded the cataclysm of war, to drape itself with Edwardian comfort. It was tired and disillusioned, and felt no victor’s triumph. The country looked to itself, and to its empire, eschewing the complications of commitments on continental Europe that had recently resulted in the loss of so much blood. The losses sustained in the Great War resulted in the overwhelming national sentiment that war must never again be undertaken as a form of politics. Clausewitz was dead. Part of this sentiment evidenced itself in the rise of pacifism.

In the army, a pervasive belief existed that the Great War was an aberration, and nothing like it would again afflict western civilisation. Any lessons from the war were therefore irrelevant to the future structures or doctrine of the British Army, for whom the defence of the Empire was the crucial issue. But whether it liked it or not, the world was changing fast, in ways that Britain struggled to comprehend and from which it could not ultimately escape.

The Russian Revolution, the rise of fascist dictators in Europe, isolationism in the U.S. (a new American assertiveness in Asia notwithstanding) and the increasing militancy of Japan, began changing the global landscape in ways that were hard to understand for a country seemingly once in total charge of the certainties of statecraft. Now it struggled to find its way in a new world of tension, turmoil and rapid change.

Failure to leverage the lessons of 1918

Third, few in the British Army thought to capture the reasons for operational success in 1918. The dramatic reduction in troops numbers at the end of the Great War meant that those best able to convert the learning from 1918 into doctrine left for civilian life, taking their knowledge and experience with them. It was never recovered. There was therefore no template in the years afterward on which to build a successful military doctrine based on the successful warfighting experience that had culminated in the victories of 1918.

Political naivety

Fourth, political naivety led to a dramatic economic stringency being applied, including the underlying Treasury assumption in the early 1920s of the “Ten Year Rule,” an assumption that kept rolling over, year after year. This meant that there wasn’t enough money to do what was necessary to protect British interests from impending harm. The butter that was the army was thinly spread across the imperial bread, with the result that insufficient investment was made in the core of the army’s warfighting capability. This stringency was exacerbated by the impact of the Great Depression at the end of the 1920s into the early years of the next decade.

New challengers

These factors coalesced with a new global instability caused by the rise of a new breed of irrational actor – in Germany, Italy and Japan – which overturned previously held notions of diplomacy and state behaviour. Britain was unprepared for this type of political discombobulation, with a form of European politics never seen before, driven by racist ideology rather than rational statecraft, especially on the continent but also in Asia Pacific. Who could have foreseen the rise of irrational national actors, prepared to lead their people into a populist (and racist) doom? Certainly, no published strategic assessments in Britain during this period understood this frightening development and had not prepared for the military manifestation of such ideas.

Adrift

As a consequence, the British Army was left to muddle through, without clear political direction and therefore without its own clearly articulated firm direction. This left it vulnerable to strategic befuddlement. With no grand strategic direction, the War Office and Chiefs of Staff were unable to create the necessary military strategy to define the purpose of the army and so direct it accordingly. This led to political imperatives asserting themselves, such as imperial garrison commitments. This doctrinal vacuum allowed competing visions for technology, doctrine and equipment to be endlessly debated, and for there to be no effective plan for the realistic equipping and training of the army in the particular tasks it would need to undertake in the next war. The army allowed itself to become intellectually moribund, boring and regimental, and a home for the uninquisitive. Consequently, the quality of military leadership was poor.

Missed opportunities

It raises a fascinating question: Could Britain have prevented the Second World War if it and its armed forces had been better prepared?

If Britain and her army, after 1919, had retained a capability able to take on a sophisticated peer adversary in Europe, and if its government had similarly retained a willingness to preserve the peace on the continent using the type of military deterrence exercised following 1949 against the U.S.S.R. (via NATO), could the Second World War have been averted?

Hitler and his Wehrmacht were nervous about possible British and French reactions to the illegal reoccupation of the Rhineland in March 1936. Berlin need not have worried. France and Britain did nothing, directly encouraging Hitler’s territorial ambitions elsewhere in Europe.

In part this was because Britain did not have at its disposal in 1938 or 1939 the mobile, all-arms formations (i.e., a corps or multiple corps) able to intervene militarily on the continent against the Wehrmacht. The British government could not threaten Germany with something it did not possess. The impressive capability it had boasted in 1918 no longer existed. The rest is history, but too many lessons from this period are too profound to be ignored in our present day. Even a casual glance at the British Army today raises the issues that this cautionary tale posits.

Lessons of history

The primary lesson from this period is that the country must have a clear and unambiguous grand strategy; and for capable and effective military authorities to be able translate this direction into a military strategy that structures, equips, and trains its armed forces to fight the country’s foes.

Because it did not do so, the leadership of the British army after 1918 fundamentally failed itself and the country it was charged with protecting, because it did not hold firm to those tactical, operational and doctrinal truths which it had mastered by the final year of the Great War. It forgot these lessons of victory, and spent the following two decades in an intellectual, structural and doctrinal torpor.

Much of the doctrinal argument of the 1920s was a distraction. It didn’t point back to 1918 and was deeply factional and tribalistic at heart. It wasn’t a centrally coordinated debate owned and directed by an army leadership determined to construct a set of doctrinal truths around which the entire army (and armed forces) would happily coalesce, based on what had been learned and understood in 1918. That had all been ditched as irrelevant to future war.

Instead, the army leadership appeared, for much of this time, to be detached observers of a domestic squabble. This failure of the army’s leadership led directly to its abysmal performance in Norway and France in 1940, its failure to understand the ingredients of battlefield success in North Africa in 1941 and 1942 and its defeat in South-East Asia in 1942. Arguably, it was only in 1944 in north-western Europe and in India and Burma that the lessons hard won in 1918, were hard won again.

The stark message of the two decades between the world wars is that we neglect to understand who our enemy might be, and how to defeat him, at the peril of our country. The book I have co-authored with General Lord Dannatt, Victory to Defeat, is not just about the failure of an army, but the failure of political and military leadership. It is the story of the decline of an army from the triumph of victory in 1918 to defeat in 1940. It is a salutary warning to us all.

Dr. Robert Lyman is a co-author of Victory to Defeat: The British Army 1918–40. One of Britain’s top military historians, he spent 20 years in the British Army and he is currently a Research Fellow at the Changing Face of War Centre, Pembroke College, University of Oxford. His most recent book, A War of Empires (Bloomsbury/Osprey, 2021), was published to critical acclaim and was shortlisted for the RUSI Medal for Military History 2022.