The “Monroe doctrine” was a foreign policy initiative by President James Monroe of United States in 1823. Since then, for a century, US’s foreign policy more or less followed the path set by the Monroe doctrine.
Spanish civil war happened just before the start of WW2, from 1936 to 1939. It was fought between the Republicans, who were loyal to the democratic, left-leaning Second Spanish Republic, and the Nationalists, a falangist(a form of fascism) group led by General Francisco Franco who ruled Spain from 1930 to 1975 as its dictator.
Italy under Mussolini had joined with Nazi Germany and Japan to form the Axis powers. He adopted fascism led his country in to another world war.
Ironically, In 1922, the King himself invited Benito Mussolini into government.
Hitler capitalized on the prevailing socio-economic and political factors prevailing in post-war Germany to become one of history’s most influential dictator. The most fascinating thing is that Hitler gained power at least initially through democratic process when he became the chancellor of Germany in 1933 and later assumed the title of ‘Fuhrer'(The leader) and ruled the Third Reich(Nazi Germany) from 1934 till his death in 1945.
There are multi-dimensional factors that led to this phenomenon:
Japan found itself on the wrong side of history during WW2 when it allied with Axis powers and invaded many countries of East Asia.
Decolonization is the process by which colonies become independent of the colonizing country.
Some take a broader look:
It means that to some extent, a movement began following WWI and gained momentum after WWII, where people around the world said that people have the right to govern themselves. However, many of the colonizing countries that lost control of governments maintained a presence in decolonize territories, often in the form of military.
Some question whether colonialism has ended:
Colonization takes many forms: from the literal appropriation of lands to cultural globalization, from political manipulation and armed intervention to modern versions of economic enslavement