From the beginning of the modern era to the second half of the 20th century, European militaries possessed a significant technological advantage, allowing its states to pursue policies of expansionism and colonization until the Cold War period.
After 2014, the Russian annexation of Crimea and the ongoing Russo-Ukrainian War prompted renewed scholarly interest into European military affairs.
Due to the numerous countries that grew out of Medieval feudalism and de-centralization from the Western Roman Empire's fall, different nations have had a power struggle.
France having the natural barriers of the Rhine to the east, the Pyrenees to the south, and the English Channel to the north has tried to maintain these throughout its history with rivalry with Britain for centuries and then with Germany.
Numerous civil wars plagued Ancient Rome for many centuries, but it was the eventual Barbarian incursion from Central and Eastern Europe which contributed the most to the fall of the Western Roman Empire.
[2] The early parts of the medieval period known as the Dark Ages saw the first conflicts with the Eastern Roman Empire which continued to fight the Persians in the Roman-Persian Wars and against the Muslim conquests shortly after.
In the Medieval period, feudalism was firmly implanted, and there existed many landlords in Europe with armored cavalry being the dominant on the battlefield.
The Ottoman Empire was formed with considerable projection into the Balkan region after finally defeating the Eastern Roman Capital of Constantinople.
The Thirty Years' War from 1618 to 1648 dominated Central Europe from the participation of all the major European powers resulting in German areas' virtual economic disintegration.
The Russian Civil War lasted from 1917 to 1922, saw the intervention of various European powers, ending in victory for the Bolsheviks and the formation of the Soviet Union.
This conflict was a prelude to the World War II, both in new technologies used (strategic and tactical aerial bombing, mechanized warfare, direct attacks on civilian populations, guerilla operations) and belligerents (Fascist Italy and Nazi Germany supporting the Nationalist side, Communist Russia and various European leftist groups supporting the Loyalist side).
World War II was a global military conflict which involved a majority of the world's nations, including all of the great powers, organised into two opposing military alliances: the Allies led by the United States, the United Kingdom, and the Soviet Union, versus the Axis powers led by Nazi Germany and Japan.
Both superpowers engaged in costly defence spending, a massive conventional and nuclear arms race, and numerous proxy wars.
The current conflict in the area of northern Macedonia and Serbian province Kosovo, where Albanian paramilitaries started guerilla war against the government forces.