Binational state

A multi-national state (most commonly a binational state or a trinational state) is a nation-state that has several distinct and (if the status of the state has come to issue at all) rival cultures within it that compete for control. It is usually an unstable situation, but can come to be stabilized for long periods if the balance of power is managed carefully.

Most such states have historically ended with one of a small range of outcomes:

federation that delegates each nation some powers within the state, e.g. as First Nations and Quebec have within Canada.
secession of one nation within the state, e.g. that of Czechoslovakia into the Czech Republic when Slovakia seceded.
civil war leading to either secession, federation, or some new balance of power that puts one nationality firmly in charge of another, e.g. the 1990s war between the Tutsis and the Hutus of Rwanda.

Language is a major issue in almost all such divergences of culture and polity. Colonization has led to many multi-national states, including the United States, Canada, Mexico and almost all of Latin America. Haiti and the Dominican Republic share the island of Dominica and speak different languages, but this is a binational island - one island with two states, like Cyprus, although one of the states present there is not recognized by any nation other than Turkey.

Assertions that any state not formally federated as such, is binational or trinational or more fragmented, is usually denied and opposed politically and militarily. Some examples:

Lebanon with its mixed Muslim and Christian population.
Spain has fought Basque separatists for decades.
Russia strongly opposed separatists in Chechnya. A referendum later established the desire of Chechens to remain within the Russian federation.
Iraq has a Kurd and Shia region, each of which has a history of political and military opposition to the Sunni region which contains the capital, Baghdad. Among the predicted effects of invading Iraq were a bloody civil war among these factions - not yet realized as of January 2004.
Turkey is strongly opposed to any declaration of statehood by Kurds in Iraq, and has militarily suppressed both the Kurd population in its own southeast, and denied them the right to use their language.
A "binational solution" is advocated by some to the Israeli-Palestinian conflict. This idea has very little support on either side of the conflict.
In Canada, assertions that Quebec was a "distinct society" were met by strong opposition from English-speaking citizens who felt that each of the provinces of Canada were just as distinct. This debate was serious enough to cause an agreement to bring Quebec formally under the Canadian Constitution failed. Another agreement failed due to overlooking First Nations as "founding peoples". Quebec remains outside the Constitution, formally. The territory of Nunavut was later created as the first fully native ruled jurisdiction in the Americas, much celebrated by indigenous peoples as an example of self-rule.
In Europe, some states, such as Belgium and Switzerland, formally recognize two or more official languages, and have remained stable for many years. Although these are admired, they are exceptions rather than the rule.

A multi-national state usually requires a great deal of work to keep together. Success or failure may be due to success or failure at creating a functional multi-ethnic society. There are however external military and economic pressures that may cause a clearly distinct society to remain within a state. Thus a multi-national state does not always imply a multi-ethnic society. There are also peoples or nations united by something other than ethnicity, like for instance religion. And, there are nations that have no states at all, or which are split among states, like the Kurds, who are poorly integrated into several societies that are weakly multi-ethnic, some of which, like Iraq or Turkey, can be said to be multi-national states.