Foreign relations of the United Kingdom

The United Kingdom was the world's foremost power during the 19th and early 20th centuries, most notably during the so-called "Pax Britannica"—a period of unrivaled supremacy and unprecedented international peace during the mid-to-late 1800s. The country continued to be widely considered a superpower until the Suez crisis of 1956, and the dismantling of the British Empire gradually diminished the UK's dominant role in global affairs. Nevertheless, the United Kingdom remains a great power and a permanent member of the United Nations Security Council. The UK is a founding member of AUKUS, the Commonwealth, the Council of Europe, the European Court of Human Rights, the G7, the G20, the International Criminal Court, NATO, the OECD, the OSCE, the World Health Organization, and the World Trade Organization, additionally the UK is a member of CPTPP. The UK was also a founding member state of the European Union, however due to the outcome of a 2016 membership referendum, proceedings to withdraw from the EU began in 2017 and concluded when the UK formally left the EU on 31 January 2020, and the transition period on 31 December 2020 with an EU trade agreement. Since the vote and the conclusion of trade talks with the EU, policymakers have begun pursuing new free trade agreements with other global partners.

In March 2026, the UK government announced that it would make deep cuts to its foreign aid budget, including a 56% reduction in bilateral aid to African countries, as funds are redirected toward defence spending.

History

Following the formation of the Kingdom of Great Britain (which united England and Scotland) in 1707, British foreign relations largely continued those of the Kingdom of England. British foreign policy initially focused on achieving a balance of power in Europe, with no single country dominating the continent's affairs. This policy remained a major justification for Britain's wars against Napoleon, and for British involvement in the First and Second World Wars. Secondly, Britain continued to expand its colonial "First British Empire" through migration and investment.

France was the chief enemy until Napoleon's defeat in 1815. It had a much larger population and a more powerful army, but a weaker navy. The British were generally successful in their many wars. The notable exception, the American War of Independence (1775–1783), saw Britain, without any major allies, defeated by the American colonials who had the support of France, the Netherlands, and (indirectly) Spain. A favoured British diplomatic strategy involved subsidising the armies of continental allies (such as Prussia), thereby turning London's enormous financial power to military advantage. Britain relied heavily on its Royal Navy for security, seeking to keep it the most powerful fleet afloat, eventually with a full complement of bases worldwide. British dominance of the seas was vital to the formation and maintenance of the British Empire, achieved by maintaining a navy larger than the next two largest navies combined before 1920. The British generally stood alone until the early 20th century, when they became friendly with the US and made alliances with Japan, France, Russia, and Germany, their former antagonist, now an ally.

1814–1914

The 100 years were generally peaceful—a sort of Pax Britannica enforced by the Royal Navy. There were two important wars, both limited in scope. The Crimean War (1853–1856) saw Russia's defeat and ended its threat to the Ottoman Empire. The Second Boer War (1899–1902) saw the defeat of the two Boer republics in South Africa, and the Boxer Rebellion happened the same year. London became the world's financial centre, and commercial enterprise expanded across the globe. The "Second British Empire" was built with a base in Asia (especially India) and Africa.

First World War

1920s

After 1918, Britain was a "troubled giant" that was less of a dominant diplomatic force in the 1920s than before. It often had to give way to the United States, which frequently exercised its financial superiority. The main themes of British foreign policy included a leading role at the Paris Peace Conference of 1919–1920, where Lloyd George worked hard to moderate French demands for revenge on Germany. He was partly successful, but Britain soon had to moderate French policy toward Germany further, as in the Locarno Treaties of 1925. Furthermore, Britain obtained "mandates" that allowed it and its dominions to govern most of the former German and Ottoman colonies.

Britain became an active member of the new League of Nations, but its list of major achievements was slight.

Disarmament was high on the agenda, and Britain played a major role, following the United States, at the Washington Naval Conference of 1921 in working toward naval disarmament among the major powers. By 1933, disarmament agreements had collapsed, and the issue became rearming for a war against Germany.

Britain was partially successful in negotiating better terms with the United States regarding the large war loans which Britain was obliged to repay. Britain supported the international solution to German reparations through the Dawes Plan and the Young Plan. After the Dawes Plan had helped stabilize Germany's currency and lowered its annual payments, Germany was able to pay its annual reparations using money borrowed from New York banks, and Britain used the money received to pay Washington. The Great Depression starting in 1929 put enormous pressure on the British economy. Britain revived Imperial Preference, which meant low tariffs within the British Empire and higher barriers to trade with outside countries. The flow of money from New York dried up, and the system of reparations and debt payments died in 1931.

In British domestic politics, the emerging Labour Party had a distinctive and suspicious foreign policy rooted in pacifism. Its leaders believed that peace was impossible because of capitalism, secret diplomacy, and the arms trade. Labour stressed material factors, ignoring the psychological memories of the Great War and the highly emotional tensions surrounding nationalism and national boundaries. Nevertheless, party leader Ramsay MacDonald devoted much of his attention to European policies.

1930s

Vivid memories of the horrors and deaths of the First World War inclined many Britons—and their leaders in all parties—to pacifism in the interwar era. This led directly to the appeasement of dictators (notably Mussolini and Hitler) to avoid their threats of war.

The challenge came from those dictators, first from Benito Mussolini, Duce of Italy, then from Adolf Hitler, Führer of a much more powerful Nazi Germany. The League of Nations proved disappointing to its supporters; it failed to resolve any of the threats posed by the dictators. British policy involved "appeasing" them in the hope that they would be satisfied. By 1938, it was clear that war was looming and that Germany had the world's most powerful military. The final act of appeasement came when Britain and France sacrificed Czechoslovakia to Hitler's demands at the Munich Agreement of September 1938. Instead of satiation, Hitler menaced Poland, and at last Prime Minister Neville Chamberlain dropped appeasement and stood firm in promising to defend Poland (31 March 1939). Hitler, however, cut a deal with Joseph Stalin to divide Eastern Europe (23 August 1939); when Germany did invade Poland in September 1939, Britain and France declared war, and the British Commonwealth followed London's lead.

Second World War

Having signed the Anglo-Polish military alliance in August 1939, Britain and France declared war against Germany in September 1939 in response to Germany's invasion of Poland. This declaration included the Crown colonies and India, which were directly controlled by Britain. The dominions were independent in foreign policy, though all quickly entered the war against Germany. After the French defeat in June 1940, Britain and its empire stood alone in combat against Germany until June 1941. The United States provided diplomatic, financial, and material support, starting in 1940, especially through Lend Lease, which began in 1941 and reached full strength in 1943. In August 1941, Churchill and Roosevelt met and agreed on the Atlantic Charter, which proclaimed "the rights of all peoples to choose the form of government under which they live" should be respected. This wording was ambiguous and would be interpreted differently by the British, Americans, and nationalist movements.

Starting in December 1941, Japan overran British possessions in Asia, including Hong Kong, Malaya, and especially the key base at Singapore. Japan then marched into Burma, headed toward India. Churchill's reaction to the United States' entry into the war was that Britain was now assured of victory, and the future of the empire was safe. Still, the rapid defeats irreversibly harmed Britain's standing and prestige as an imperial power. The realisation that Britain could not defend them pushed Australia and New Zealand into permanent close ties with the United States.

Postwar

Economically in dire straits in 1945 (saddled with debt and dealing with widespread destruction of its infrastructure), Britain systematically reduced its overseas commitments. It pursued an alternate role as an active participant in the Cold War against communism, especially as a founding member of NATO in 1949.

The British had built up a very large worldwide Empire, which peaked in size in 1922, after more than half a century of unchallenged global supremacy. The cumulative costs of fighting two world wars, however, placed a heavy burden upon the home economy. After 1945, the British Empire rapidly disintegrated, with all the major colonies gaining independence. By the mid-to-late 1950s, the UK's status as a superpower had been eclipsed by the United States and the Soviet Union. Most former colonies joined the "Commonwealth of Nations", an organisation of fully independent nations now with equal status to the UK. However it attempted no major collective policies. The last major colony, Hong Kong, was handed over to China in 1997. Fourteen British Overseas Territories maintain a constitutional link to the UK, but are not part of the country per se.

Britain slashed its involvements in the Middle East after the humiliating Suez Crisis of 1956. However, Britain forged close military ties with the United States, France, and Germany through NATO. After years of debate (and rebuffs), Britain joined the Common Market in 1973, which became the European Union in 1993. However it did not merge financially, and kept the pound separate from the Euro, which partly isolated it from the Euro area crisis. In June 2016, the UK voted to leave the EU.

21st century

Foreign policy initiatives of UK governments since the 1990s have included military intervention in conflicts and for peacekeeping, humanitarian assistance programmes and increased aid spending, support for establishment of the International Criminal Court, debt relief for developing countries, prioritisation of initiatives to address climate change, and promotion of free trade. The British approach has been described as "spread the right norms and sustain NATO".

Lunn et al. (2008) argue:

Three key motifs of Tony Blair's 10-year premiership were an activist philosophy of 'interventionism', maintaining a strong alliance with the US and a commitment to placing Britain at the heart of Europe. While the 'special relationship' and the question of Britain's role in Europe have been central to British foreign policy since the Second World War...interventionism was a genuinely new element.

The GREAT campaign of 2012 was one of the most ambitious national promotion efforts ever undertaken by any major nation. It was scheduled to take maximum advantage of the worldwide attention to the Summer Olympics in London. The goals were to make British culture more visible to stimulate trade, investment, and tourism. The government partnered with key leaders in culture, business, diplomacy, and education. The campaign unified many themes and targets, including business meetings, scholarly conventions, recreational vehicle dealers, parks and campgrounds, convention and visitors bureaus, hotels, bed-and-breakfast inns, and casinos.

In 2013, the government of David Cameron described its approach to foreign policy by saying:

For any given foreign policy issue, the UK potentially has a range of options for delivering impact in our national interest. ... [W]e have a complex network of alliances and partnerships through which we can work.... These include – besides the EU – the UN and groupings within it, such as the five permanent members of the Security Council (the "P5"); NATO; the Commonwealth; the Organisation for Economic Cooperation and Development; the G8 and G20 groups of leading industrialised nations; and so on.

The UK began establishing air and naval facilities in the Persian Gulf, located in the United Arab Emirates, Bahrain, and Oman in 2014–15. The Strategic Defence and Security Review 2015 highlighted a range of foreign policy initiatives of the UK government. Edward Longinotti notes how current British defence policy is grappling with how to accommodate two major commitments, to Europe and to an ‘east of Suez’ global military strategy, within a modest defence budget that can only fund one. He points out that Britain's December 2014 agreement to open a permanent naval base in Bahrain underlines its gradual re-commitment east of Suez. By some measures, Britain remains the second most powerful country in the world by virtue of its soft power and "logistical capability to deploy, support and sustain [military] forces overseas in large numbers." Although commentators have questioned the need for global power projection, the concept of "Global Britain" put forward by the Conservative government in 2019 signalled more military activity in the Middle East and Pacific, outside of NATO's traditional sphere of influence.

At the end of January 2020, the United Kingdom left the European Union, with a subsequent trade agreement with the EU in effect from 1 January 2021, setting out the terms of the UK-EU economic relationship and what abilities the Foreign, Commonwealth & Development Office can use in foreign relations related to trade.