What is nationalism and what effect did it have on europe in the early 1900s?

Nationalism is pride in one's country and some people in the mid 1900s took it to an extreme (like Hitler and Stalin) as for the early 1900s im not sure but that is what nationalism is

Nationalism is pride in one's country and some people in the mid 1900s took it to an extreme (like Hitler and Stalin) as for the early 1900s im not sure but that is what nationalism is

“destroyers for bases agreement in the destroyers for bases agreement between the united states and the united kingdom on september 2, 1940, fifty caldwell , wickes, and clemson class us navy destroyers were transferred to the toyalbnavy from the united states navy in exchange for land rights on british possessions.” i hope this you .