Power projection
History: Early examples of power projection include Roman dominance of Europe and the wider Mediterranean basin: the ability to project power is tied to the ability to innovate and field such innovations. Roman engineering innovations such as machines (pile driver), concrete, aqueducts and modern roads provided the footing for an economic engine that powered a military that was unmatched in its day. Examples of Roman power projection include Julius Caesar constructing the Rhine bridge in 10 days to demonstrate the ability to march his 40,000 troops as he saw fit: the local inhabitants enjoyed the natural protection of the river and fled when this natural protection was overcome. Although Rome is far from the center of modern power, its influence can be seen in the architecture of modern capitols around the world (domes, arches, columns). The demonstration of an extraordinary innovative military capability will signal power and, when properly applied, terminate conflicts summarily.
During the Ming treasure voyages in the 15th century, the Chinese treasure fleet was heavily militarized to exercise power projection around the Indian Ocean and thereby promote its interests.
The modern ability to project power and exert influence on a global scale can be tied to innovations stemming from the Industrial Revolution and the associated modernizations in technology, communications, finance and bureaucracy; this finally allowed the state to create unprecedented amounts of wealth and to effectively marshal these resources to exert power over long distances.
As the birthplace of the Industrial Revolution, Britain was the first to utilize its industrial-technological power advantage to dominate rivals and greatly expand its global Empire throughout the 19th century. As a maritime power, the Royal Navy played a central role in providing Britain the strength and ability to dominate world trade and project power globally to further its interests. A worldwide system of naval bases and coaling stations, a large logistical bureaucracy to oversee shipbuilding, the supply of coal, food, water, and sailors, and an industrial base for the manufacture and technological enhancement of the fleet were among the essential ingredients for this capability. During the First Opium War (1839–1842), it was this capacity that enabled a British expeditionary force of 15 barracks ships, 4 steam-powered gunboats and 25 smaller boats with 4,000 marines to successfully defend its interests 6,000 miles (9,700 km) from the fleet's home port.

The Anglo-French expeditionary force sent to shore up the Ottoman Empire against Russian aggression during the Crimean War (1853–1856) was one of the earliest modern examples of a planned expeditionary power-projection campaign. It was the first campaign to use modern technology, including steam-powered warships and telegraph communications.
Another illustrative example of industrial power projection, was the British Expedition to Abyssinia in 1868 as a retaliation against Emperor Tewodros II of Ethiopia's imprisonment of several missionaries and British government representatives. The expeditionary force sent was a tremendous logistical and technological challenge at the time. Commanded by Lieutenant-General Sir Robert Napier of the Bombay Army, military intelligence was used to estimate the required size of the army and the difficulties of traversing the inhospitable terrain.
A force of over 30,000 was shipped from British India to Zula on the Red Sea on a fleet of more than 280 steam ships, while an advance detachment of engineers built a large port with two piers, warehouses and a lighthouse, and constructed a 20-mile (32 km)-long railway towards the interior. A road was also built for the artillery to be moved along with the help of elephants. After three months of trekking, the British force repelled an Ethiopian attack and launched an artillery bombardment against the fortress of Magdala which led to its capitulation; Tewodros committed suicide.
In the Russo-Japanese War of 1904–1905, the Japanese destruction of the Imperial Russian Navy's Pacific Fleet demonstrated Imperial Russia's inability to project force in the East. This immediately diminished Russia's diplomatic sway in that region. At the same time, Russia's western armies became less credible, as mobilization exposed organizational flaws and threw the western armies into chaos. This led analysts in Europe, such as German chief of staff Count Alfred von Schlieffen, to conclude that Russia would prove inept at projecting force in Europe, thus demoting Russia in European diplomatic relations.
Many other actions can be considered projections of force. The 19th century is full of incidents such as the 1864 Shimonoseki campaign and the Boxer Rebellion. More recently, the Falklands War provided an example of the United Kingdom's ability to project force far from home. Other recent examples of power projection include the U.S.-led invasion of Iraq and the NATO bombing of Yugoslavia. The ability of the U.S. Navy, the British Royal Navy, and the French Navy to deploy large numbers of ships for long periods of time away from home are notable projection abilities. See § Power projection capabilities.
The globalization of power projection was long avoided in the research with the subject of globalization mostly channeled to economic field, but in 2018 Historian Max Ostrovsky broke the path. In prehistory, he wrote, power was not projected behind entrance of a cave. In history, empires and colonies projected power ever farther, creating world system c. 1900. World Wars were expressions of power projected on global scale.
The potential of power projection can be estimated mathematically by calculating the speed of transportation and communication relatively to the extent of contemporary power projection. Roman troops moved 50 km per day; today Globemasters move troops 20,000 km per day. The speed of communication in the largest Empire in Americas (Inca) was 20 km per hour (running man); today it moves with the speed of light. Multiplying the range of power projection in those empires by increase in the speed of transportation or communication, Ostrovsky estimated the present power projection potential to exceed the size of Earth multiple times.

Elements: The U.S. Department of Defense defines power projection as the "ability of a nation to apply all or some of its elements of national power—political, economic, informational, or military—to rapidly and effectively deploy and sustain forces in and from multiple dispersed locations to respond to crises, to contribute to deterrence, and to enhance regional stability".
As distance between a fighting force and its headquarters increases, command and control inevitably becomes more difficult. Modern-day power projection often employs high-tech communications and information technology to overcome these difficulties, a process sometimes described as the "Revolution in Military Affairs".
While a few long-range weapons such as the intercontinental ballistic missiles (ICBMs) and some unmanned combat aerial vehicles (drones) are capable of projecting deadly force in their own right, it is military logistics that is at the heart of power projection. The ability to integrate naval and air forces with land armies as part of joint warfare is a key aspect of effective power projection; airlift and sealift capabilities facilitate the deployment of soldiers and weapons to a distant theater of war.
The aircraft carrier strike group, strategic bomber, ballistic missile submarine, and strategic airlifter are all examples of power projection platforms. Military units designed to be light and mobile, such as airborne forces (paratroopers and air assault forces) and amphibious assault forces, are utilized in power projection. Forward basing is another method of power projection, which, by pre-positioning military units or stockpiles of arms at strategically located military bases outside a country's territory, reduces the time and distance needed to mobilize them.

Types: Scholars have disaggregated military power projection into nine different categories based on political goals and level of force. Four of these employ "soft" military power (securing sea lanes of communication, non-combatant evacuation, humanitarian response, and peacekeeping) and the rest are primarily concerned with "hard" military power (show the flag, compellence/deterrence, punishment, armed intervention, and conquest). There is a § continuum in these capabilities.

Soft power: Examples of soft power projection include:

Securing sea lanes of communication: the protection of shipping lanes from attack by hostile states or irregular threats.
Non-combatant evacuation operations: the evacuation of citizens or friendly third-country civilians from a foreign country when they are endangered by war or civil unrest.
Humanitarian response: the use of military forces abroad to assist in the aftermath of a natural disaster.
Peacekeeping: military operations designed to support diplomatic efforts to reach a long-term political settlement to an ongoing dispute.
Establishing trust, as the basis of cooperation among allies and partners

Gray zone competition: This section has been split from US Army Futures Command § Other armies
The gray zone between cooperation and conflict has expanded due to the competition in power projection capabilities of the world's armies, as well as in the competition for economic power among the world's nations. 

The US, Russia, China, Britain, and France have renounced the use of nuclear weapons in 2022. However, in the face of threats of nuclear war (say from Russia, as threatened during the 2022 Russian invasion of Ukraine), NATO keeps about 100 B61 nuclear bombs in storage in Europe.: 4:50, 5:55  Certain F-35As were certified to carry the B61 nuclear bomb on 12 October 2023. 
The British Army is investigating innovations, such as robots and drones, including 70 technologies funded by the £800 million (US$1 billion) Defence Innovation Fund launched in 2016. Two hundred troops will engage in "surveillance, long-range, and precision targeting, enhanced mobility and the re-supply of forces, urban warfare and enhanced situational awareness".