Geopolitics, Regional Alliances, and Devolution

Geopolitics is the study of how geography (location, resources, distance and borders) influences power and politics between states, regional alliances are groups of countries that cooperate on defense, trade or politics, and devolution is the transfer of powers from a central government to regional governments within a state. In brief: classic theories include Mackinder’s Heartland (1904), Mahan’s sea power and Spykman’s Rimland. Alliances range from military pacts such as NATO to economic and political unions such as the European Union and ASEAN. Devolution, as in Scotland, Wales and Catalonia, responds to regional identities and demands for self-government and can strengthen or strain the unity of the state.

Power operates at global, regional and local scales, and political geographers study all three. This guide explains the main geopolitical theories, how and why alliances are formed, the forces that unite or divide states, and how devolution works, compares the alliances in a table, works through calculations, outlines the history and corrects common mistakes.

What is geopolitics and what are its main theories?

• Sea power (Alfred Thayer Mahan, 1890): control of the seas and trade routes gives a state global power. It influenced the naval expansion of Britain, the United States and Germany.
• Heartland theory (Halford Mackinder, 1904): the Eurasian interior, the “Heartland,” is a pivot of world power because of its size and resources. Mackinder summarized it as: “Who rules East Europe commands the Heartland; who rules the Heartland commands the World Island; who rules the World Island commands the World.” Critics note that air power and technology have changed the importance of land.
• Rimland theory (Nicholas Spykman, 1944): the coastal belt around Eurasia (Western Europe, the Middle East, South and East Asia) is the key, and not the Heartland. This idea supported the American policy of containment during the Cold War.
• Domino theory: the Cold War idea that if one country fell to communism, its neighbors would follow, used to justify involvement in Vietnam.
• Modern approaches: critical geopolitics examines how leaders use geographic stories to justify action, and new themes include control of energy and minerals, the Arctic, cyberspace and space.

Geopolitics is also shaped by the German concept of Lebensraum (living space), which was misused to justify Nazi expansion, and which discredited geopolitics for decades.

What are regional alliances?

Alliances and blocs form for security, trade or political reasons. A military alliance is a mutual defense pact. NATO (the North Atlantic Treaty Organization), founded in 1949, has 32 members after Finland (2023) and Sweden (2024) joined, and its Article 5 says that an armed attack on one is an attack on all. Economic and political unions pool trade, rules and sometimes sovereignty. The European Union (27 members) has a single market, common trade policy, shared institutions and a common currency, the euro, which is used by most members. ASEAN in Southeast Asia, the African Union (55 members), Mercosur and USMCA in the Americas, the Arab League, the Shanghai Cooperation Organisation and BRICS are other examples. A supranational organization, such as the EU, has powers above those of the individual states in some areas.

Countries join to gain security, bigger markets, a stronger voice and shared infrastructure. Limits include the loss of some independence, disagreements among members, unequal power and, as the UK’s 2016 referendum showed, popular opposition. Brexit took effect in 2020.

What is devolution?

Devolution is the delegation of powers by a central government to regional or local governments, without changing the sovereignty of the state. The United Kingdom devolved powers in 1998–1999: Scotland has its own Parliament, Wales the Senedd and Northern Ireland an Assembly, each with powers in areas such as health, education and local government. In Spain, 17 autonomous communities have wide powers, and Catalonia and the Basque Country have strong identities and demands for more autonomy. Belgium has become a federal state in stages since 1970 to give communities and regions more power, and Italy, France and others have decentralized some functions. Federalism is a constitutional division of power, which cannot be changed unilaterally by the center, while devolved powers can in principle be withdrawn by the central parliament.

Reasons for devolution include regional identity (language, history), economic differences, a wish for local decisions that fit local needs and a way of reducing separatist pressure. Supporters say it brings government closer to people and recognizes diversity. Critics fear that it creates inequalities between regions, duplicates bureaucracy and may encourage demands for independence. Referendums have tested these issues: in 2014, Scotland voted 55.3% to 44.7% to remain in the UK, and in 2017, Catalonia held an unauthorized independence referendum, which the Spanish government and courts declared illegal.

What forces unite or divide a state?

The geographer Richard Hartshorne in 1950 described centripetal forces, which bind a state together (a shared national identity, strong institutions, a common language or religion, symbols, effective government, a successful economy and external threats), and centrifugal forces, which pull it apart (regional or ethnic divisions, economic inequality, conflicts over resources, poor transport links, weak government and outside interference). A state is stable when centripetal forces dominate. Devolution can be a way of managing centrifugal forces.

Alliances compared

Worked example: votes, shares and weights

1. Referendum result: in the 2014 Scottish referendum, about 2.00 million voted “No” and 1.62 million voted “Yes”. The total is about 3.62 million, so “No” had 2.00 ÷ 3.62 = 55.3% and “Yes” had 44.7%. The margin was 10.6 percentage points.
2. Turnout: if 3.62 million people voted out of an electorate of 4.28 million, turnout was 3.62 ÷ 4.28 = 84.6%.
3. Share of the population: if a devolved region has 5.4 million people in a country of 67 million, it has 5.4 ÷ 67 = 8.1% of the population. If it produces 7.5% of national output, its output per head is 7.5 ÷ 8.1 = 0.93 of the national average.
4. Defense spending target: NATO’s long-standing guideline was for members to spend 2% of GDP on defense (a higher target was agreed in 2025). For a country with a GDP of 800 billion, 2% is 0.02 × 800 = 16 billion.
5. Share of a bloc: if a bloc has a total GDP of 18,000 billion and a member has a GDP of 4,200 billion, the member’s share is 4,200 ÷ 18,000 = 23.3%. In a voting system weighted by population, a member with 83 million of 447 million people has 83 ÷ 447 = 18.6% of the votes.
6. Qualified majority: if a decision requires 55% of states and 65% of the population, a proposal backed by 15 of 27 states (55.6%) representing 60% of the population passes the first test but fails the second.

How have these ideas developed?

Alliances have been features of international politics for centuries, such as the Concert of Europe after 1815 and the opposing alliance systems before the First World War. The Cold War divided the world between NATO (1949) and the Warsaw Pact (1955, dissolved in 1991). European integration began with the European Coal and Steel Community (1951) and the Treaty of Rome (1957), and developed into the European Union with the Maastricht Treaty (1992–93). Devolution became prominent in the 1990s with new institutions in the UK and the federalization of Belgium and Spain, and in the 21st century, issues of regional autonomy and independence continue in Catalonia, Scotland, Quebec, Kurdistan and elsewhere. Geopolitical rivalry in the 21st century has focused on Eurasia, the Indo-Pacific, the Arctic and control of technology and resources.

Which mistakes are common?

Mistake 1: Treating geopolitical theories as laws

They are interpretations based on particular periods and technologies. They help to explain some policies, but they can also be used to justify them.

Mistake 2: Confusing devolution with federalism or independence

Devolution transfers powers that can in principle be withdrawn. Federalism divides power constitutionally. Independence creates a new sovereign state.

Mistake 3: Seeing all alliances as military

Many are economic or political, such as the EU, ASEAN and USMCA. NATO is a defense alliance.

Mistake 4: Assuming that joining an alliance means giving up all sovereignty

Members keep their sovereignty but agree to limits in specific areas. The degree varies from loose cooperation to deep integration.