In United Kingdom, the British military is a highly regarded and experienced force with a long history, a global presence, and a wide range of missions and responsibilities; these responsibilities include protecting the UK, its territories, national interests, and values, preventing conflict, providing humanitarian assistance, participating in international peacekeeping, building relationships, and fulfilling the UK’s alliance and treaty commitments; in addition to its role in the UN, the UK is a leading member of NATO and has made considerable military contributions to NATO missions in such places as Afghanistan, the Baltics, and Iraq, as well the Baltic and Mediterranean seas and the waters of the North Atlantic; it is also a member of the Five Power Defense Arrangements (FPDA), a series of mutual assistance agreements reached in 1971 embracing Australia, Malaysia, New Zealand, Singapore, and the UK; in 2014, the UK led the formation of the Joint Expeditionary Force (JEF), a pool of high-readiness military forces from the Baltic and Scandinavian countries able to respond to a wide range of contingencies both in peacetime and in times of crisis or conflict; the UK military also has strong bilateral ties with a variety of foreign militaries, particularly the US, with which it has a mutual defense treaty; British and US military forces have routinely operated side-by-side across a wide range of operations; other close military relationships include Australia, France, and the Netherlands; in 2010, for example, France and the UK signed a declaration on defense and security cooperation that included greater military interoperability and a Combined Joint Expeditionary Force (CJEF), a deployable, combined Anglo-French military force for use in a wide range of crisis scenarios, up to and including high intensity combat operations

the British Army is divided into a Field Army and a Home Command; the Field Army has three divisions, including one comprised of light forces and designed for expeditionary operations, a heavy division with armored and mechanized brigades, and a specialized division that brings together special operations, intelligence, reconnaissance, electronic warfare, and information operations capabilities; the Army also has some independent brigades and aviation forces

the Royal Navy conducts operations globally and has a sustained presence in the Baltic, Caribbean, and Mediterranean seas, the Middle East, and the South Atlantic Ocean, and increasingly in the Pacific Ocean; it is organized into a surface fleet, a submarine service, a fleet air arm, marines, and a fleet auxiliary, which is a civilian support branch that provides logistical and operational support to military operations; the heart of the surface fleet are two aircraft carriers, the largest and most advanced warships ever built for the Royal Navy, which serve as the fleet’s flagships; the carriers are complemented by six destroyers and 14 frigates, as well as two large amphibious assault ships and flotillas of patrol and mine warfare vessels; the Navy also has nine attack submarines and four ballistic missile submarines that form the UK's strategic nuclear deterrent force; the air arm has modern, US-made multirole fighter aircraft, as well as anti-submarine capable helicopters; the Royal Marines have an amphibious infantry/commando brigade and special forces

the Royal Air Force also conducts operations globally and has a wide variety of aircraft types and capabilities, including fighter, surface attack, airborne early warning and control, intelligence, surveillance, target acquisition, reconnaissance, signals intelligence, maritime patrol, air-to-air refueling, and transport organized into groups, stations, and squadrons; it has a mix of more than 150 modern European- and US-made multirole fighter aircraft

in addition, the British military has a Space Command (established in 2021) staffed by Army, Navy, and Air Force personnel, as well as civilians and key members of the commercial sector to manage space operations, training, and capabilities; it established a joint service National Cyber Force in 2020; in 2019, the UK formed the joint service Strategic Command to develop and manage the British military's medical services, training and education, defense intelligence, and information systems, as well as joint overseas operations; national-level special forces (UK Special Forces) also fall under the Strategic Command

the British Armed Forces were formed in 1707 as the armed forces of the Kingdom of Great Britain when England and Scotland merged under the terms of the Treaty of Union; while the origins of the armed forces of England and Scotland stretch back to the Middle Ages, the first standing armies for England and Scotland were organized in the 1600s while the navies were formed in the 1500s; the Royal Marines were established in 1755; the Royal Air Force was created in April 1918 by the merger of the British Army's Royal Flying Corps and the Admiralty's Royal Naval Air Service (2023)