By the end of the 20th century, as this quote from Mary Kaldor highlights, the casualties of armed conflicts were more likely to be civilians than soldiers:
In the Korean War (1950-53) between the regimes in the north and the south but also involving China, the Soviet Union, the United States and other UN forces, which is often called the first proxy war of the Cold War, somewhere between 2 and 3 million civilians died. (approximately two-thirds of the total casualties).
In the 1st Sudan Civil War between the north and south of the country (1955-72) around half a million people died and it is estimated that 80% were non-combatants.
In the Vietnam War (1955-75) fought between North Vietnam and its communist allies on one side and South Vietnam and its non-communist allies, particularly the United States, estimates vary as to the total number of deaths but average around 3 million of which two-thirds were civilians.
The Chinese Cultural Revolution (1966-76) instigated by Chairman Mao Zedang against the “revisionists” who were alleged to be anti-communist led to the persecution of many millions of Chinese people. Accurate statistics of casualties are not available but the numerous estimates average out at around 1 million deaths and around 20 million sent to labour camps..
In 1967 the south-eastern region of Nigeria declared independence as the Republic of Biafra. The three-year war that followed led to over a million deaths. It is estimated that 75-80% were civilians dying mainly from starvation.
According to Professor Mary Kaldor of the London School of Economics:
The tendency to avoid battle and to direct most violence against civilians is evidenced by the dramatic increase in the ratio of civilians to military casualties. At the beginning of the twentieth century 85-90 per cent of casualties in war were military. In World War II approximately half of all war deaths were civilians. By the late 1990s, the proportions of a hundred years ago have been almost exactly reversed, so that nowadays approximately 80 percent of all casualties in wars are civilians.
New and Old Wars: Organised violence in a Global Era, Cambridge Polity Press(1999) p.100