Are there cases where a civil war divided a country unevenly but stably, like China and Taiwan?

Question

The Chinese Civil War split the Republic of China into the victorious People's Republic of China and the defeated Republic of China (Taiwan).

This split appears to have been extremely one-sided, with the victors obtaining almost all of the land and population. In 1950, mainland China had 500 million population (compared to about 7 million for Taiwan, under 2%), and the land area of Taiwan is about a quarter of a percent of mainland China's.

Normally, one would expect that such an uneven split would be unstable, and the defeated party would soon be conquered in its entirety. The relative defensibility of insular territory and American military support against Communism allowed Taiwan to survive in our timeline. That being said, this appears to be a rare instance and I was unable to find any other cases where this happened from a quick search.

Are there any other historical cases where a civil war divided a country in such an uneven manner and resulted in a stable outcome? For the purposes of this question, I will set the criteria as:

1. The smaller country has <2% population of total
2. The smaller country has <2% land area of total
3. The two (or more) states must remain de facto independent for at least 50 years after the civil war.

If there are no such examples that fit the (admittedly arbitrary) criteria based on Taiwan, other examples are also welcome.

Answer 1

The criteria you set are quite extreme. Here are some examples that do not quite meet all of them, in part because the longer you go back in time, the more terms like "country", "independence", and "territory" turn out to be modern projections that do not really fit the political realities of the time. In late medieval times, the cities of northern Italy fought against the German Emperor to gain the right to govern themselves, and often succeeded (see the Duchy of Milan and the Republic of Venice). But none of them ever would have considered that they were not his subjects.

Old Swiss Confederacy vs. Holy Roman Empire

Formally, Switzerland was accepted by the European powers as independent from the German Empire/the Habsburg monarchy in the Peace of Westphalia of 1648. But the process of gaining self-governance started somewhere in the 13th/14th century with the Bundesbriefe (Federal charters) that tried to establish a self-organised Landfrieden, while not challenging the role of the nobility and its feudal basis inside that Empire.

Dutch Republic vs. Spanish Empire

The territory of what today encompasses the Netherlands, Belgium, Luxembourg and parts of northern France belonged to the Spanish Empire since 1522, when the House of Habsburg split into an Austrian and a Spanish line. The northern provinces insurrected against the Spanish rule after 1579, leading to eighty years of war. The United Provinces of the Netherlands were acknowledged as an independent state also in the Peace of Westphalia.

Finland vs. Soviet Union

Finland had been part of the Russian Empire since 1809. After the Russian February revolution of 1917, the Finish parliament entered negotiations with the Russian Provisional Government about its independence. Its declaration of independence from November 1917 was accepted by the Bolshevik government at the end of the year. Despite (or because of) that, a civil war broke out between German-backed republican and Soviet-backed socialist forces, ultimately won in April 1918 by the "Whites".

The last one is from recent times, so despite the split having a high probability to endure, it has not yet existed for 50 years. Also, the split is nearer to 10 : 1 than your 50 : 1.

Eritrea vs. Ethopia

Eritrea came under Italian colonial rule in the late 19th century, Ethiopia in 1936, when the two countries were merged. After independence, under a ruling by the United Nations, both countries formed a federation. Ethopian Emperor Haile Sellasie challenged the seperate identity of Eritrea during the 1950ties and its autonomy was finally rescinded in 1962. Since then the Eritreans fought back, and in 1993 declared their independence after a successfull referendum.

Answer 2

Thinking of even/uneven/one-sided is misleading here. What really results in a split is the impossibility for one side to completely defeat the other, which can be for military, political, economic and other reasons. E.g., the fact that Taiwan is an island certainly made it difficult to overrun it, and the US support has contributed to the "stability" of the situation.

Once we take account that "stable" situation is a balance of many different factors, the examples become abundant:

• North and South Korea
• Israel and Palestine (Israel arguably have the military might to overrun the Palestine, and in fact did so in 1967, but the resulting situation was politically and demographically untenable and resulted in later concessions)
• Northern and Southern Cyprus
• Eastern Ukraine (from 2014 till February 2022)
• Northern Ireland and the Republic of Ireland
• Israeli and Syrian occupation of Lebanon for about a quarter of a century - here presence of foreign armies was the "stabilizing" factor, but one could argue that Lebanon is still divided, with central government not really able to control certain areas

One could find more examples by reading about Frozen conflicts. What might seem ambiguous is how to qualify a conflict as a civil war vs. a war between two states, since this is often the matter of dispute that led to the conflict.