“Until August 1914 a sensible, law-abiding Englishman could pass through life and hardly notice the existence of the state, beyond the post office and the policeman.
He could live where he liked and as he liked. He had no official number or identity card. He could travel abroad or leave his country for ever without a passport or any sort of official permission. He could exchange his money for any other currency without restriction or limit. He could buy goods from any country in the world on the same terms as he bought goods at home. For that matter, a foreigner could spend his life in this country without permit and without informing the police. Unlike the countries of the European continent, the state did not require its citizens to perform military service. An Englishman could enlist, if he chose, in the regular army, the navy, or the territorials. He could also ignore, if he chose, the demands of national defence. Substantial householders were occasionally called on for jury service. Otherwise, only those helped the state who wished to do so. The Englishman paid taxes on a modest scale: nearly £200 million in 1913-14, or rather less than 8 percent of the national income… [B]roadly speaking, the state acted only to help those who could not help themselves. It left the adult citizen alone.
All this was changed by the impact of the Great War. The mass of the people became, for the first time, active citizens. Their lives were shaped by orders from above; they were required to serve the state instead of pursuing exclusively their own affairs. Five million men entered the armed forces, many of them (though a minority) under compulsion. The Englishman’s food was limited, and its quality changed, by government order. His freedom of movement was restricted; his conditions of work prescribed. Some industries were reduced or closed, others artificially fostered. The publication of news was fettered. Street lights were dimmed. The sacred freedom of drinking was tampered with: licensed hours were cut down, and the beer watered by order. The very time on the clocks was changed. From 1916 onwards, every Englishman got up an hour earlier in summer than he would otherwise have done, thanks to an act of parliament. The state established a hold over it citizens which, though relaxed in peacetime, was never to be removed and which the second World war was again to increase.”
Pulled from the opening chapter “The Effects and Origins of the Great War” in A. J. P. Taylor’s English History, 1914-1945.
In The New Cambridge Modern History: 1898-1945, there’s a substantial discussion of this link between the First and Second World Wars and the rise of the modern administrative state. A summary paragraph:
Until after 1847 direct income tax had been a device almost peculiar to Great Britain… During the 1890s, pari passu with the great expansion of governmental expenditures on armaments as well as on social services, Germany and her component states, as well as Italy, Austria, Norway, and Spain, all introduced or steepened systems of income tax. French governments repeatedly shied away from it, though they resorted to progressive death duties in 1901, and it was 1917 before a not very satisfactory system of income tax was introduced. The great fiscal burdens of war accustomed people to heavier taxation.
In 1920, Paul Cambon, France’s ambassador to Britain, told Winston Churchill, “In the twenty years I have been here I have witnessed an English Revolution more profound and searching than the French Revolution itself.” He continued, “The governing class have been almost entirely deprived of political power and to a very large extent of their property and estates; and this has been accomplished almost imperceptibly and without the loss of a single life.” Cambridge summarizes this: “If M. Cambon was exaggerating in 1920, he was perceptively prophetic, for his description became substantially true after the second world war.”