Expansionism is the doctrine of expanding the territory or economic influence of a country.

There are several countries with expansionist aims today, though this the state in question may not take kindly to being labelled 'expansionist.' One form of expansionism is the ideology of creating a 'Greater' state. This usually takes the form of unifying a people or particular ethnic group (e.g. Somalia, Albania).

Expansionism can often overlap with irredentism, when one country seeks to take back territories that once belonged to them, or even to take over ancestral lands. It may also overlap with a simple territorial dispute, such as a border dispute. This type of dispute is not usually called expansionism.

Modern Expansionism

• Akhand Bharat (seeks to create an enlarged India)
• Greater Albania (seeks to unite all ethnic Albanians in an enlarged state).
• Greater Hungary (seeks unite all ethnic Hungarians in an enlarged state).
• Greater Mongolia (seeks unite all ethnic Mongolians in an enlarged state).
• Greater Morocco (seeks to expand Moroccan territory to encompass areas ruled by the Almoravid Empire in the past)
• Greater Romania (seeks unite all ethnic Romanians in an enlarged state, specifically to absorb Moldova into Romania).
• Greater Somalia (seeks to unite all Somalis in an enlarged state).
• Reconquista (seeks to include south-west America in an enlarged Mexico)

Past Expansionism

• Afghanistan sought to create an enlarged Greater Afghanistan , specifically to absorb land inhabited by Pashtuns in the North West Frontier Province in modern Pakistan
• Croatia sought to create an enlarged ethnically 'pure' Greater Croatia
• Greece sought to expand it's territory in order to have all Greeks united (Enosis) in one country
• Italy (during the rule of Benito Mussolini) sought to enlarge it's territory in Europe
• Japan sought to expand it's territory in Asia during the inter-war years
• Nazi Germany sought to unite all ethnic Germans and take land in the east (see Lebensraum)
• Serbia sought to create an enlarged ethnically 'pure' Greater Serbia
• United States of America sought to expand from coast-to-coast as part of the idea of Manifest Destiny (at the expense of Native Americans)