The correct answer to this open question is the following.
"By last quarter of nineteen-century nationalism no longer retained its idealistic liberal -democratic sentiment of the first half of century, but became a narrow creed with limited ends".
The meaning of this quote is the following.
At the end of the 1800s, nationalism ended its concept of a liberal nation and turned into defiant and intolerant nations that supported hate against other nations. People formed groups that exhibited intolerant attitudes against other nations or ethnicities, which was the root of many conflicts to come, include the beginning of World War I.
Some European superpowers fed this nationalistic sentiment to declare wars or pressure other nations, as was the case of the conflict in the Balkans region in 1871. This region grouped many ethnicities that today are the countries of Romania, Bulgaria, Croatia, Slovenia, Serbia, Bosnia, among others. Here the major conflicts exploded.
