I grew up at the dawn of nuclear warfare and The Cold War, the latter an ideological conflict between the United States and its allies and the Soviet Union and its satellites. I also was growing up when European colonialism crumbled sometimes peacefully, but often through armed conflict.

The more recent conflicts have included wars on terrorism with the fallout from the 9/11 attacks in the United States leading to the invasions by America and its allies into Afghanistan, Iraq, and Syria.

In the 20th century, wars killed more than 160 million. The tally for the 21st century is estimated to be another 20 million to date. But both of these numbers are a significant undercount when you consider the collateral deaths that accompany human conflicts.

The wars of the 20th century featured technological innovation and the restructuring of national economies focused on the mass production of weapons. Two of these wars were global lasting many years. The losers of these 20th-century conflicts saw the emergence of social upheaval, civil war and regime change. A list of 38 of the most notable of these conflicts follows:

1. The Boer War in South Africa, 1899–1902
2. World War One, 1914–1918
3. Russian Revolution and Civil War, 1917 – 1922
4. The Irish War of Independence and Civil War, 1919-1923
5. The Turkish War of Independence, 1919 – 1923
6. The Japanese Invasion of Manchuria, 1931
7. Italo-Ethiopian War, 1935 – 1936
8. The Spanish Civil War, 1936–1939
9. The Arab Revolt in Palestine, 1936-1939
10. The Japanese-China War, 1937 – 1945
11. World War 2 in Europe, 1939 – 1945
12. World War 2 in the Pacific, 1941 – 1945
13. The Palestine Conflict, 1944 -1948
14. The Cold War, 1945 – 1991
15. The Chinese Civil War, 1945 – 1949
16. The Partition of India War, 1947
17. Arab-Israeli Conflict, 1948 – 1949
18. The British-Malay War, 1948 – 1960
19. The Korean War – 1950 – 1953
20. The Kenyan Mau Mau Rebellion, 1952 – 1960
21. The Algerian War of Independence, 1954 – 1962
22. The Vietnam War, 1955 – 1975
23. The Suez Crisis, 1956
24. The Eritrean War of Independence, 1961 – 1991
25. The War of Malay, Brunei and Indonesian Independence, 1962 – 1966
26. The Six-Day War between Israel, Egypt, Jordan, and Syria, 1967
27. The Nigerian Civil War, 1967 – 1970
28. The Northern Ireland Troubles, 1969 – 1998
29. The Yom Kippur War, Israel, Egypt and Syria, 1973
30. The Ogaden Ethiopian-Somali War, 1977 – 1978
31. The Argentine-Falkland Islands War, 1982
32. The Kuwait-Iraq Gulf War, 1990 – 1991
33. Sierra Leone Civil War, 1991–2002
34. The Yugoslav Wars – Slovenia, 1991, Croatia, 1991 – 1995, Bosnia and Herzegovina – 1992 – 1995, Kosovo, 1998 – 1999
35. The Somali Civil War, 1992 – ongoing
36. The Rwandan Genocide, 1994
37. The Congo Civil War, 1997 – 1999
38. The Eritrean – Ethiopian War, 1998 – 2000

The legacy of the 20th century has carried on into the 21st. That legacy includes nuclear, planet-killing weapons, ballistic missiles and more. A growing number of militaries have these capabilities in their armaments. And yet there are even more changes to come as technology alters the battlefields in the 21st century.

So what is changing? Cyberwarfare has opened up an entirely new theatre of war taking it to the Internet, making data networks, energy, and civil infrastructure vulnerable to disruptions. Wars for the minds of people, today, include mass dissemination of misinformation using social media and search engines.

Warfare may soon extend to near-Earth space. Anti-satellite weapons have been tested by Russia and China. Others will soon do the same.

Finally, human warfare is likely to be supplemented by machine-to-machine conflicts as remote-guided and autonomous weapon systems, artificial intelligence, and robotics get deployed on 21st-century future battlefields. The age of killer robots is near, something in the past confined to science fiction novels. That’s why, since 2018, the United Nations has been trying to organize an agreement among nations to draft a treaty banning the use of anti-personnel autonomous weapons in conflicts. How effective have UN bans been in deterring war? Unfortunately, not very.

A final note. Have you heard of the Mad Scientist Initiative? Formed by TRADOC, the United States Army Training and Doctrine Command in the last decade, among its many pursuits were surrounding human soldiers with better technology that included enhancing combatant protection and awareness using Iron Man armour and neural-link implants, the latter, to create human-computer interfaces. Welcome to a real 6-million-dollar man.

If this subject interests you, I recommend you read a paper entitled, “Technology, war and the state: past, present and future,” published in the journal, International Affairs.