In November of 2018 we in Great Britain remembered the centenary anniversary of the end of the first world war. This war was mainly fought in Europe on two fronts, a Western Front through France and an Eastern Front in Russia. Germany with the support of Austria-Hungary, Turkey and Bulgaria had fought France, Britain, Russia, Italy (changed to this side 1915), Japan and from 1917 the United States. The war extended beyond Europe because the participants had extensive and sometimes adjacent colonies in Africa as well as a few in the far east. The war was also a war at sea.
In 2019 we remembered the 75th anniversary of the D Day landings of 1944 that led to VE (Victory Europe) day in the May of 1945. The D represented an unknown invasion Day when British, Canadian and US troops would try to set free the German occupied territories of France, Belgium, The Netherlands, Denmark, Poland, Greece and Yugoslavia. That day turned out to be the 6th of June 1944. But again and even more so this war was a world war. The Japanese Empire (they did not surrender until the September of 1945) and the Italian Fascists were in full support of Nazi Germany. In opposition were Great Britain, troops from the British Empire, the Free French, the Russians from 1941, the USA (from December 1941 -after the Japanese attack on Pearl Harbour) and China (who had been at war with Japan from 1937).
You may have ancestors who were involved in these wars. If so you share that with lots of people throughout the world who had ancestors killed or injured or who suffered in some other way as a result of the wars. Statistics concerning the numbers of dead, missing and wounded can often be estimates that are give or take a few million. So the figures I give below are estimates only and intended to show that these wars were not just about us. They were world wars.

In the four and a quarter years of the first world war it is estimated that about 20 million died, half of which were civilians. Add to that a figure of over 20 million wounded and we get a feel for the human loss and suffering of this war.
The table reveals that whilst Russia had at 1.8 million the highest deaths of military personnel, the civilian deaths to Ottoman Turks were at 2.1 million even higher and Serbia’s 16.1% loss of its population is indicative of the suffering there.
Not included in the table are figures for North, East and West Africans who fought and assisted in the war both in Europe and in Africa. About 71, 000 African soldiers are recorded as having died fighting in Europe but there is also an unknown loss of African labourers there. Not so much is known about the soldiers and labourers that died fighting in the European owned African colonies. One estimate says about 155,000 labourers died in the East African conflicts alone.

World war 2 lasted 6 years from 1939 to 1945. 70 or more million people, some 3% of the world pre-war population are estimated to have died as a result.
In war a country’s control and boundary may rapidly change and supply chains become chaotic. Populations can be displaced, moved or even lost to starvation. Occupying forces may take most resources and treat populations harshly and thereby contribute to significant deaths. Some occupied countries do not accept accept their new masters and so adopt guerilla tactics that likewise add to deaths.
Available stats have huge errors so my table of deaths is illustrative only and makes no reference to what must be similar numbers of injured. Each figure will have its own unique explanation that you can discover if you so wish.
The table shows the United Kingdom fared better in ww2 than in ww1. Its loss of about 400,000 is much the same as the USA loss (of which about 100,000 was in the far east). Both losses are dwarfed by the near 27 million loss of the USSR (In Belarus about 25% of the population died). It is also small in relation to losses in Poland, China, Yugoslavia, French IndoChina, the Dutch East Indies, Germany, Japan and India whose total deaths all exceeded one million.
Ww2 did not just involve the ambitions of Hitlers Nazi party and of Mussolini’s Italian Fascists. Japan’s Emperor Hirohito was already extending his empire in the East and sought to take advantage of the war by taking colonies that were in the possession of European powers and the USA . Japanese actions at Pearl Harbour on Hawaii in 1941 brought America into the war.
Wherever there were colonies they were involved. Colonies might be required to supply troops for use in the war (Germany had many Africans fighting in Europe). C olonial peoples would be required to defend the colony or fight against a neighbour colony. Many colonial peoples suffered greatly at the hands of occupiers and particularly where they were the subject of battles. There losses might have been comparatively small yet highly significant to them.
War was about human desires that lead to confrontation. Those same human desires to dictate and dominate are still there in this world today. In Europe we may be war free but the majority are still controlled by the few and Governments support that scenario. O for a world of sensible but freely given cooperation where people only take their essential needs of food and security from the environment. It would be a happier less stressed world for all.