Edexcel IGCSE History: The Changing Nature of Warfare and International Conflict, 1919–2011 (4HI1)

Breadth Study B6, “The changing nature of warfare and international conflict, 1919–2011”, is one of eight breadth studies in change in Section B of Pearson Edexcel International GCSE History (4HI1) Paper 2. It traces how war on land, at sea and in the air changed over almost a century — from the lessons of the First World War, through Blitzkrieg, strategic bombing and aircraft carriers in the Second World War, to nuclear deterrence, guerrilla wars, high-technology conflict and drones. Questions focus on change, continuity and the significance of new weapons and methods.

Related: Revision notes | Practice questions | Paper 2 overview

Syllabus coverage

The specification (Issue 5, February 2026) names five themes: land warfare; sea warfare; air warfare; weaponry, technology and communications; and guerrilla warfare. The (c) essay normally draws on two or more key topics. The five key topics are:

1. The changing nature of warfare, 1919–39 — gas, tanks and heavy artillery; submarines and military aircraft, including fighters and bombers in East Asia and Abyssinia; guerrilla tactics in the Spanish Civil War.
2. Changing methods of warfare by land, air and sea, 1939–45 — Blitzkrieg, the Battle of Britain, the Blitz, V weapons and the Allied bombing of Germany; U-boat warfare in the Atlantic; amphibious and paratrooper operations (D-Day and Arnhem); civilian resistance, especially in France; aircraft carriers in the Pacific War.
3. Nuclear and guerrilla war versus conventional war, 1945–75 — the atomic bombs, the nuclear arms race, other weapons of mass destruction and their delivery, MAD and proliferation, arms limitation; conventional war in the Arab–Israeli conflicts; superpowers and guerrilla war, especially in Vietnam.
4. Conventional war and “new” wars, 1976–2000 — the first Gulf War, the Falklands and carrier warfare, nuclear submarines, guerrilla war in Afghanistan, “Star Wars” and the end of the nuclear arms race.
5. Warfare at the beginning of the 21st century, 2000–2011 — terrorism and 9/11, high-tech war and “surgical” air strikes in the Middle East, drone war in Pakistan and unmanned land vehicles in Iraq and Afghanistan.

How did warfare change between the wars, 1919–39?

The First World War had introduced gas, tanks and massed heavy artillery. Between the wars, theorists argued that fast tanks with air support could restore movement to the battlefield, though few armies fully adopted the idea before 1939. Gas was banned by the Geneva Protocol (1925), but Italy used it in Abyssinia (1935–36). Submarines were developed further despite treaty limits. Military aircraft became faster and more powerful: Japanese bombers attacked Chinese cities in the 1930s, and Italian aircraft bombed Abyssinian forces and villages. In the Spanish Civil War (1936–39), German aircraft bombed Guernica (1937), and Republican forces used guerrilla tactics behind the lines.

How did methods change in the Second World War?

Land. German Blitzkrieg (“lightning war”) combined tanks, motorised infantry and dive-bombers, with radio communication, to break through and encircle enemy forces — conquering Poland (1939) and France (1940) in weeks.

Air. In the Battle of Britain (1940) the RAF, helped by radar and a coordinated control system, defeated the Luftwaffe’s attempt to win air superiority. The Blitz (1940–41) bombed British cities. Late in the war Germany launched V-1 flying bombs and V-2 rockets. The Allies’ strategic bombing of Germany, by the RAF at night and the US air force by day, destroyed cities such as Hamburg (1943) and Dresden (1945); its effectiveness in reducing German production is debated.

Sea. In the Battle of the Atlantic, U-boat “wolf packs” attacked convoys; convoys, long-range aircraft, improved radar, escort carriers and code-breaking defeated them by mid-1943. In the Pacific War (1941–45) aircraft carriers replaced battleships as the decisive ships: Pearl Harbor (1941) was a carrier raid, and the Battle of Midway (1942) was won by carrier aircraft.

Combined operations. D-Day (6 June 1944) was the largest amphibious landing in history, with paratroopers dropped behind the beaches. At Arnhem (September 1944) an airborne attempt to seize Rhine bridges failed. Civilian resistance movements, especially in France, sabotaged railways and gathered intelligence.

How did nuclear and guerrilla war change conflict, 1945–75?

The USA dropped atomic bombs on Hiroshima and Nagasaki in August 1945 to end the war quickly without an invasion — and, some argue, to impress the USSR. The nuclear arms race followed: Soviet atomic bomb (1949), hydrogen bombs (early 1950s), intercontinental ballistic missiles and submarine-launched missiles, and multiple warheads. Chemical and biological weapons were also developed. Mutually Assured Destruction (MAD) meant neither superpower could attack without being destroyed itself. Britain, France and China acquired bombs, so proliferation became a fear; the Test Ban Treaty (1963), the Non-proliferation Treaty (1968) and SALT I (1972) tried to limit the race.

Conventional war remained important, especially in the Arab–Israeli wars: in 1967 Israeli air strikes destroyed Arab air forces on the ground, and in 1973 Egyptian forces crossed the Suez Canal under cover of surface-to-air missiles. Superpowers struggled with asymmetric guerrilla war, above all in Vietnam, where US firepower could not defeat an enemy that used tunnels, ambushes and popular support.

What changed between 1976 and 2000?

In the Falklands War (1982) Britain sent a task force led by two small aircraft carriers with Harrier jets. The nuclear-powered submarine HMS Conqueror sank the Argentine cruiser General Belgrano, and Argentine Exocet missiles sank British ships, showing the vulnerability of surface vessels. In the first Gulf War (1991) a US-led coalition used a long air campaign with precision-guided weapons, cruise missiles from ships and submarines and stealth aircraft before a ground offensive that lasted about 100 hours. In Afghanistan (1979–89) Soviet forces were worn down by mujahideen guerrillas, armed later with US-supplied Stinger missiles; the USSR withdrew in 1989. Reagan’s Strategic Defense Initiative (“Star Wars”, 1983) proposed a space-based missile shield, adding pressure on the USSR; the INF Treaty (1987) and the end of the Cold War brought the nuclear arms race to an end, followed by cuts under START.

How did warfare change in 2000–2011?

The 9/11 attacks (2001), when al-Qaeda hijackers flew airliners into the World Trade Center and the Pentagon, showed the power of terrorism and led to the US-led invasion of Afghanistan (2001) and, in 2003, of Iraq. These wars combined high-tech warfare — satellite-guided bombs and “surgical” air strikes meant to hit targets precisely — with long counter-insurgency campaigns against roadside bombs. Drones such as the Predator and Reaper carried out strikes in Pakistan, controlled from thousands of miles away, and unmanned ground vehicles were used to find and defuse bombs in Iraq and Afghanistan.

Frequently asked questions

What is the biggest change across the period? The rise of air power, culminating in nuclear weapons and drones, is often argued; continuity lies in the importance of ground forces and guerrilla resistance.

Why did superpowers struggle against guerrillas? Guerrillas avoided battle, relied on local support and could outlast foreign forces’ political will.

Did nuclear weapons make conventional war obsolete? No — Arab–Israeli wars, the Falklands and the Gulf War show its continuing importance.

Official syllabus

Pearson Edexcel International GCSE History (4HI1) specification, Issue 5, February 2026, Paper 2, Breadth Study B6 — qualifications.pearson.com.