The arms industry, also known as the defense industry or the arms trade, is a global industry responsible for the manufacturing and sales of weapons and military technology. It consists of a commercial industry involved in the research and development, engineering, production, and servicing of military material, equipment, and facilities. Arms-producing companies, also referred to as arms dealers, defence contractors, or as the military industry, produce arms for the armed forces of states and civilians. Departments of government also operate in the arms industry, buying and selling weapons, munitions and other military items. An arsenal is a place where arms and ammunition are made, maintained and repaired, stored, or issued, in any combination, whether privately or publicly owned. Products include guns, artillery, ammunition, missiles, military aircraft, military vehicles, ships, electronic systems, night vision devices, holographic weapon sights, laser rangefinders, laser sights, hand grenades, landmines and more. The arms industry also provides other logistical and operational support.
Stockholm International Peace Research Institute (SIPRI) estimated that 2012 military expenditures were roughly $1.8 trillion. This represents a relative decline from 1990 when military expenditures made up 4% of world GDP. Part of the money goes to the procurement of military hardware and services from the military industry. The combined arms sales of the top 100 largest arms-producing companies amounted to an estimated $395 billion in 2012 according to SIPRI. In 2004 over $30 billion were spent in the international arms trade (a figure that excludes domestic sales of arms). According to SIPRI, the volume of international transfers of major weapons in 2010–14 was 16 per cent higher than in 2005–2009. The five biggest exporters in 2010–2014 were the United States, Russia, China, Germany and France, and the five biggest importers were India, Saudi Arabia, China, the United Arab Emirates and Pakistan.Many industrialized countries have a domestic arms-industry to supply their own military forces. Some countries also have a substantial legal or illegal domestic trade in weapons for use by its citizens, primarily for self-defence, hunting or sporting purposes. Illegal trade in small arms occurs in many countries and regions affected by political instability. The Small Arms Survey estimates that 875 million small arms circulate worldwide, produced by more than 1,000 companies from nearly 100 countries.Contracts to supply a given country's military are awarded by governments, making arms contracts of substantial political importance. The link between politics and the arms trade can result in the development of what U.S. President Dwight D. Eisenhower described as a military-industrial complex, where the armed forces, commerce, and politics become closely linked, similarly to the European multilateral defence procurement. Various corporations, some publicly held, others private, bid for these contracts, which are often worth many billions of dollars. Sometimes, as with the contract for the international Joint Strike Fighter, a competitive tendering process takes place, with the decision made on the merits of the designs submitted by the companies involved. Other times, no bidding or competition takes place.