The cause of Polish nationalism was repeatedly frustrated before 1918. In the 1790s, Prussia, Russia and Austria partitioned Poland . Napoleon set up the Duchy of Warsaw , a new Polish state that ignited a spirit of nationalism. Russia took it over in 1815 as Congress Poland with the tsar as King of Poland. Large-scale nationalist revolts erupted in 1830 and 1863–64 but were harshly crushed by Russia, which tried to Russify the Polish language, culture and religion. The collapse of the Russian Empire in the First World War enabled the major powers to reestablish an independent Poland, which survived until 1939. Meanwhile, Poles in areas controlled by Germany moved into heavy industry but their religion came under attack by Bismarck in the Kulturkampf of the 1870s. The Poles joined German Catholics in a well-organized new Centre Party , and defeated Bismarck politically. He responded by stopping the harassment and cooperating with the Centre Party.  
To summarize, WW1 left a massive mark in the society we live in today. Many people had died from uncontrollable forces which were raging to show off their society. Nationalism triggered the World War as countries tried to show others what they were capable of. When nationalism spread itself around Europe, it angered many as many important figures were assassinated and left a massive mark which angered thousands. Nationalism led to the death of Archduke Franz Ferdinand when he selected a Serbian national holiday to parade through Sarajevo, stoking nationalist distaste. When Ferdinand was killed, as a symbol of hatred against Austria and Serbia, since countries were allied within each other, a small local war became the largest and most dangerous war our planet has ever seen. Besides the assassination of the Archduke, there was another major cause which many people believed in. The alliance system gathered societies together swearing that if any help is needed, the other societies that swore to help must do their best to achieve their responsibilities. When two countries clashed into each other, they called in for help and alliances took place shortly after. World War one has left an indulging mark on the 20th century that will never be forgotten , even thousands and million years later on.