Alliance, League, Coalition, Fusion, Confederacy, Confederation and Federation all agree in the idea of combination, chiefly political, for a common object.
Alliance applies particularly to a joining of interests on the part of families (by marriage) or of states (by compact or treaty); it is also less formally used of a connection for mutual benefit between other bodies, organized or not.
- a defensive alliance
- an alliance between producers and consumers
League though often used without distinction from alliance typically suggests a more formal compact or more definite object and may frequently (unlike alliance) be taken in a bad sense.
- the Solemn League and Covenant
- to be in league with the powers of darkness
Coalition refers to a temporary alliance of otherwise opposing interests, parties, or factions.
- Mr. Fox, and his famous coalition with Lord North
- a coalition government
Fusion is a coalition of political parties for the purpose of defeating another party in an election.
- a fusion of Republicans and independent Democrats in New York City opposed the Tammany Democratic ticket
Confederacy and confederation apply specifically to a union by compact or treaty of independent states under a government to which powers are delegated for dealing primarily with common external relations.
- the Southern Confederacy
- the Articles of Confederation
- the German Confederation
Federation in its broad sense includes any union under the terms of a league or covenant but specifically it designates a sovereign state or city formed by the union of other states or cities with a central general government and several local governments.
- the Federation of Labor
- the United States of America constitutes a. federation
- federation was the name given to the scheme for blending the Five Towns into one town
- the Federation of Malaysia