Editing History of the United Kingdom (section)

===First World War===
{{Main|British entry into World War I|History of the United Kingdom during the First World War}}
On 4 August 1914, the King declared war on Germany and Austria, following the advice of Prime Minister [[H. H. Asquith]] of the [[Liberal Party (UK)|Liberal Party]]. The rest of the Empire automatically followed. The cabinet's basic reasons for declaring war focused on a deep commitment to France and avoidance of splitting the Liberal Party. Top Liberals led by Asquith and Foreign Secretary [[Edward Grey, 1st Viscount Grey of Fallodon|Edward Grey]] threatened to resign if the cabinet refused to support France. That would deeply split the party and mean loss of control of the government to a coalition or to the Unionist (i.e. Conservative) opposition. However, the large antiwar element among Liberals, with David Lloyd George as spokesperson, would support the war to honour the 1839 treaty that guaranteed Belgian neutrality. So Belgium rather than France was the public reason given. Posters took the line that Britain was required to go to war to safeguard Belgium's neutrality under the 1839 [[Treaty of London (1839)|Treaty of London]].<ref>{{Cite book |last=Lee |first=Stephen J. |title=Aspects of British Political History 1914–1995 |date=2005 |isbn=9781134790401 |pages=[https://books.google.com/books?id=LKGFAgAAQBAJ&pg=PA21 21]–22|publisher=Routledge }}; {{Cite journal |last=Gilbert |first=Bentley B. |date=1985 |title=Pacifist to interventionist: David Lloyd George in 1911 and 1914. Was Belgium an issue? |journal=The Historical Journal |volume=28 |issue=4 |pages=863–885 |doi=10.1017/S0018246X00005100 |jstor=2639325 |s2cid=159564885}}; {{Cite book |last=Steiner |first=Zara S. |title=Britain and the origins of the First World War |date=1977 |pages=235–237}}</ref>

[[File:The Scrap of Paper - Enlist Today.jpg|thumb|"The Scrap of Paper – Enlist Today", a 1914 British propaganda poster, emphasizes German contempt for the 1839 treaty that guaranteed Belgian neutrality as merely a "scrap of paper" that Germany would ignore.]]
Britain actually entered the war to support France, which had entered to support Russia, which in turn had entered to support Serbia. Britain became part of the [[Triple Entente]] with France and Russia, which (with smaller allies) fought the [[Central Powers]] of Germany, Austria and the Ottoman Empire. After a few weeks the [[Western Front (World War I)|Western Front]] turned into a killing ground in which millions of men died but no army made a large advance. The main British contribution was financial—loans and grants helped Russia, Italy and smaller allies afford the war.<ref>{{Cite book |last=Siegel |first=Jennifer L. |title=For Peace and Money: French and British Finance in the Service of Tsars and Commissars |date=2014 |isbn=9780199387816 |page=[https://books.google.com/books?id=nc6iBAAAQBAJ&pg=PA7 7]|publisher=Oxford University Press }}</ref>

The stalemate required an endless supply of men and munitions. By 1916, volunteering fell off, the government imposed conscription in Britain (but not in Ireland) to keep up the strength of the [[British Army during the First World War|Army]]. With his slow start and mobilization of national resources, H. H. Asquith had proven inadequate: he was more of a committee chairman, and he started to drink so heavily after midday that only his morning hours were effective.<ref>{{Cite book |last=Owen |first=David |title=The Hidden Perspective: The Military Conversations 1906–1914 |date=2014 |isbn=9781908323675 |pages=[https://books.google.com/books?id=k1crDwAAQBAJ&pg=PT78 115]–116 |publisher=Haus |quote=by modern diagnostic standards, Asquith became an alcoholic while Prime Minister. |author-link=David Owen}}</ref> Asquith was replaced in December 1916 with the much more effective [[David Lloyd George]]. He had strong support from Unionists and considerable backing of Labour, as well as a majority of his own Liberal Party, although Asquith turned hostile. Lloyd George answered the loud demands for a much more decisive government by setting up a new small war cabinet, a cabinet secretariat under [[Maurice Hankey]], and a secretariat of private advisors in the '[[The Garden Suburb|Garden Suburb]]'; he moved towards prime ministerial control.<ref>{{Cite journal |last=Morgan |first=Kenneth O. |date=2017 |title=7 December 1916: Asquith, Lloyd George and the Crisis of Liberalism |journal=Parliamentary History |volume=36 |issue=3 |pages=361–371 |doi=10.1111/1750-0206.12318}}</ref>

Britain eagerly supported the war, but Irish Nationalist opinion was divided: some served in the British Army, but the [[Irish Republican Brotherhood]] plotted an [[Easter Rising]] in 1916. It quickly failed but the brutal repression that followed turned that element against Britain, as did failed British plans to introduce conscription in Ireland in 1917.<ref>{{Cite journal |last=Munck |first=Ronald |date=1986 |title=Rethinking Irish Nationalism: The Republican Dimension |journal=Canadian Review of Studies in Nationalism |volume=14 |pages=[https://books.google.com/books?id=u7gjAQAAIAAJ 31–48]}}</ref>

The nation now successfully mobilised its manpower, womanpower, industry, finances, Empire and diplomacy, in league with France and the U.S. to defeat the enemy.<ref>{{Cite book |last=Beckett |first=Ian F. W. |title=The Great War: 1914–1918 |date=2007 |publisher=Pearson/Longman |isbn=978-1-40-581252-8 |edition=2nd}}; {{Cite book |last=Beckett |first=Ian F. W. |title=The Home Front, 1914–1918: How Britain Survived the Great War |date=2006 |publisher=Bloomsbury Academic |isbn=978-1-90-336581-6}}; {{Harvp|Marwick|1965}}</ref> The [[British Army]] had traditionally never been a large employer in the nation, with the regular army standing at 250,000 at the start of the war.<ref name="Tibus">[http://users.tibus.com/the-great-war/figures.htm The Great War] {{Webarchive |url=https://web.archive.org/web/20051109083130/http://users.tibus.com/the-great-war/figures.htm |date=9 November 2005 }} in figures.</ref> By 1918, there were about five million people in the army and the fledgling [[Royal Air Force]], newly formed from the [[Royal Naval Air Service]] (RNAS) and the [[Royal Flying Corps]] (RFC), was about the same size of the pre-war army. The economy grew about 14% from 1914 to 1918 despite the absence of so many men in the services; by contrast the German economy shrank 27%. The War saw a decline of civilian consumption, with a major reallocation to munitions. The government share of GDP soared from 8% in 1913 to 38% in 1918 (compared to 50% in 1943). The war forced Britain to use up its financial reserves and borrow large sums from New York banks. After the U.S. entered in April 1917, the Treasury borrowed directly from the U.S. government.<ref>{{Cite book |last=Stevenson |first=David |title=With Our Backs to the Wall: Victory and Defeat in 1918 |date=2011 |isbn=978-0-67-406226-9 |page=[https://books.google.com/books?id=06KYLGALKNEC&pg=PA370 370]|publisher=Harvard University Press }}; {{Harvp|Stevenson|2011|page=[https://books.google.com/books?id=06KYLGALKNEC&pg=PA370 370]}}; {{Cite book |last=Ferguson |first=Niall |title=The Pity of War |date=1998 |isbn=978-0-71-399246-5 |page=249 |publisher=Penguin Press |author-link=Niall Ferguson}}</ref>
[[File:The Battle of the Somme, July-november 1916 Q1608.jpg|thumb|[[Royal Fusiliers|Royal Fusiliers (City of London Regiment)]] in November 1916]]
The Royal Navy dominated the seas, defeating the smaller German fleet in the only major naval battle of the war, the [[Battle of Jutland]] in 1916. Germany was blockaded, leading to an increasing shortage of food. Germany's naval strategy increasingly turned towards use of [[U-boat]]s to strike back against the British, despite the risk of triggering war with the powerful neutral power, the United States. Berlin declared the water routes to Britain were war zones where any ship, neutral or otherwise, was a target. Nevertheless, international route law required giving the crew and passengers an opportunity to get into their lifeboats. In May 1915, a U-boat, without warning, torpedoed the British passenger liner [[RMS Lusitania|Lusitania]]; it sank in 18 minutes, drowning over 1000 civilians including over 100 Americans. Vigorous protests by American President Woodrow Wilson forced Berlin to abandon unrestricted submarine warfare. With victory over Russia in 1917, the German high command now calculated it could finally have numerical superiority on the Western Front. Planning for a massive spring offensive in 1918, it resumed the sinking of all merchant ships without warning, even if they were flying the American flag. The US entered the war alongside the Allies (without officially joining them), and provided the needed money and supplies to sustain the Allies' war efforts. The U-boat threat was ultimately defeated by a convoy system across the Atlantic.<ref>{{Cite book |last=Halpern |first=Paul |title=A Naval History of World War I |date=2012 |publisher=Naval Institute Press |isbn=978-0870212666 |ol=1414849M |author-link=Paul Halpern}}</ref>

On other fronts, the British, French, New Zealanders, Australians, and Japanese seized Germany's colonies. Britain fought the Ottoman Empire, suffering defeats in the [[Gallipoli campaign]] and in [[Mesopotamia]] (Iraq), while arousing the Arabs who helped expel the Turks from their lands. Exhaustion and [[war-weariness]] were growing worse in 1917, as the fighting in France continued with no end in sight. After defeating Russia, the Germans tried to win in the spring of 1918 before the millions of American soldiers arrived. They failed, and they were overwhelmed by August and finally accepted an Armistice on 11 November 1918, that amounted to a surrender.{{Sfnp|Stevenson|2011|page=249–252, 534–544}}

British society and government were radically transformed by the repeated calls for manpower, the employment of women, the dramatic increase in industrial production and munitions, price controls and rationing, and the wide and deep emotional patriotism dedicated to winning the war. Parliament took a backseat, as new departments bureaus committees and operations were created every week, experts were consulted, and the prime minister's [[Orders in Council]] replaced the slow legislative process. Even after peace arrived, the new size and dynamism had permanently transformed the effectiveness of British government.{{Sfnp|Mowat|1955|pages=13–14}} David Lloyd George, also a Liberal, was the high-powered Minister of Munitions who replaced Asquith in late 1916. He gave energy and dynamism to the war effort with his remarkable ability to convince people to do what he wanted and thus get ideas put into actual useful high-speed motion. His top aide Winston Churchill said of Lloyd George: "He was the greatest master of the art of getting things done and of putting things through that I ever knew; in fact no British politician my day has possessed half his competence as a mover of men and affairs."{{Sfnp|Mowat|1955|page=10}}

Victorian attitudes and ideals that had continued into the first years of the 20th century changed during the First World War. The almost three million casualties were known as the "[[Lost Generation]]", and such numbers inevitably left society scarred. The lost generation felt its sacrifice was little regarded in Britain, with poems like [[Siegfried Sassoon]]'s ''Blighters'' criticising the ill-informed [[jingoism]] of the home front. The lost generation was politically inert, and never had its chance to make a generational change in political power. The young men who governed Britain in 1914 were the same old men who governed Britain in 1939.<ref>{{Harvp|Mowat|1955|pages=9, 201, 216, 25}}; {{Cite journal |last=Winter |first=Jay M. |author-link=Jay Winter |date=1977 |title=Britain's 'Lost Generation' of the First World War |journal=Population Studies |volume=31 |issue=3 |pages=449–466 |doi=10.1080/00324728.1977.10412760 |jstor=2173368 |pmid=11630506 |postscript=none}} covers the statistical history of military service and death.</ref>