Greetings! On the contrary, the British found it much easier to recruit (or at times conscript) troops into their various colonial armed services than into the British Army proper. This response will deal with that consideration in more depth, as well as reveal why the size British Army prior to the First World War was markedly lower than its European counterparts. In the process, we shall also discuss the strategies which the British Empire relied on (or believed were the most effective) at maintaining its security both within the European community and beyond. Let's begin.

The Army and the Empire

"We cannot provide for a fighting empire, and nothing will give us the power. A peaceful empire of the old type we are fit for."

- Sir Henry Campbell-Bannerman, Prime Minister of the UK (r. 1905 - 1908), remarking in 1903 about the empire's security.

By the turn of the 20th century, the British Empire was, as OP has stated, the pre-eminent imperialist power in the world. In terms of sheer size and presence, the British dwarfed most of the other European powers; only France and a rising German Empire were perhaps comparable (though to far lesser extents) in terms of overseas colonies and possessions. Yet the British Empire, by its very nature, was a maritime empire. The Royal Navy, not the Army, was the pride and joy of the nation. Its squadrons kept secure the imperial shipping routes, its ships were often at the cutting edge of propulsion and armament systems, and it was often the ultima ratio of Whitehall. Throughout the 1800s, the "gunboats" of the British Empire had become synonymous with the Union Jack, and even European leaders (Russia most of all) came to bemoan the sight of a British fleet exercising in the region.

Why was this the case? Geographically speaking, it makes sense that British Army was much smaller in size than its European counterparts. To attempt any invasion of the Home Isles, one would first have to control the English Channel or the North Sea long enough to land ground forces. Napoleon himself remarked on this objective with his plans for an invasion of the British Isles:

"Let us be master of the Strait for six hours, and we shall be masters of the world."

Thus, in the debates which raged in the House of Commons regarding military matter, the army was relegated to secondary importance over the Navy. The Admiralty and various governments of the nineteenth century worried over how best to spread out its ships and where to station the squadrons. This "navalist" focus, if you will, was the hallmark of British imperial defense policy for much of the 19th century. We shall explore how this strategy would have played out in the next part of the response, but here is a good quote from naval historian Andrew Lambert on the significance of the RN:

"The potent theatre of a British fleet at exercise, with its precise, silent drill and effortless seamanship, struck fear into the hearts of rivals. Because the Royal Navy was credited with enormous power, the security of the British Empire was maintained for a pittance."

In tandem with the geographical considerations, we also have to understand the domestic reasons why the British Army was not as well-staffed or indeed, as quantitatively vast as any of the other great powers. Here, the answer is fairly straightforward: Britain did not have a general conscription law at all during the 19th century. Its army was filled with voluntary recruits and commanded by officers (usually) from the upper classes. In this way, it was alone in Europe. All the major powers (Russia, France, Austria-Hungary, and Germany) passed mass conscription laws during the same time period, whilst Britain instead focussed on increasing naval expenditure. Even in 1914, as OP has alluded to, the planned size of the British Army was less than a fourth of the size of those on the continent.

Again we must ask why this number was allowed to be as low as it was. The first part of a possible answer there lies in something we shall term "the imperial factor", the British Empire's defense required a relatively large military presence not just in the Home Isles, but also in various colonies and outposts across the world, where the British "held the keys" to lock up the region. Chief amongst all these defense regions was The British Raj, or India. From the crushing of the Sepoy Mutiny in 1859, the British maintained no less than a third of their Army in India (between 60,000 - 70,000 troops), supplemented by a local force of almost double the size. It was much the same situation in various "pocket contingents" across the other imperial possessions. Colonial recruitment was not hard, but these troops were not intended to be used in a continental war with other European powers. They were meant to be the local armed response units which dealt with any insurgents, internal violence, or (particularly in the case of South Africa), as "border guards" against external raids. Granted, these troops were often used as part of expeditionary forces during the 19th century, but these had been deployed (with the notable exception of the Crimean War) against non-continental rivals. Ashley Jackson on this amalgam of colonial peacekeeping forces:

"They [imperial defense garrisons] were supplied by a British Army rarely more than 200,000 strong in peacetime, though supplemented by a unique asset, the Indian Army, and a gallimaufry of colonial forces such as the Transjordan Frontier Force, the South Persia Rifles, the New South Wales Corps, the Northern Rhodesia Regiment, the Fiji Volunteer Force, and the Hong Kong and Singapore Garrison Artillery."

Building further on this idea of imperial defense, we must also recognise that these troops were not trained or equipped in dealing with equal, if not superior, counterparts. Since the end of the Crimean War up until the Second Boer War of 1899, the Army had been engaged in colonial conflicts, against foes which more often that not possessed outdated weapons and employed ineffective tactics for the age. Its European rivals on the other hand, wielded (aside than being much larger) modern weapons and tactics. John Darwin on this difference:

"On colonial battlefields, individual resource and the brute courage of a professional army substituted for the staff skills and modern tacts prized by continental generals. 'Dash at the first fellows that make their appearance', said Wellington, the greatest of the 'sepoy generals', 'and the campaign will be ours.'"

Behind the British government's motivation not to introduce a mass conscription law was its unpopular perception both within the government and the public. Such a law, they believed, was a symbol of absolutist despotism. Furthermore, unlike many of the European powers, the British had not faced a "national" or "people's" war in the nineteenth century such as those which had propelled France to near-mastery of the continent in the 1810s, or those which gave rise to the nation-states of Italy and Germany in the latter half. Jorn Leonhard on what this all meant:

"Thus the concepts of a nation in arms or a people's war retained a foreign connotation which, in the eyes of [British] contemporaries, could neither be applied to Britain's present situation nor to her history."

Even as late as 1899, on the eve of the Second Boer War, Prime Minister Lord Salisbury remarked on the army's ability to wage war effectively against "first-class" continental opponents to Lord Lansdowne (then Secretary of State for War):

"Our army will not find itself in that condition in a blue moon. What they ought to practise is the rapid expedition of a relatively small force to any point in the Empire where it might be wanted. Your business is that of a military fire brigade..."

So to sum this part of the response, the British Empire's Army pre-World War 1 was small for a various number of geopolitical reasons. In maintaining such a large empire, the British did not find it troublesome to recruit locals into all manner of colonial auxiliary forces, but these troops were not honed for the purpose of fighting a war with the other continental armies of Europe. Further, we have the lack of a general conscription law, and the resulting reliance on volunteers for the army. Finally, the grand "imperial strategy" for war dictated an emphasis on the Navy, and not the Army. It was squadrons and ships, not soldiers and sabers, which would deliver victory into Britannia's arms. We shall turn to this "navalist" focus next.

Part 1 of 2