Nationalism, Imperialism and Alliances: Discuss the goals of European nationalism and "new imperialism" in the late nineteenth century. Identify the various alliances among nations. How did the alliance system in Europe in the early 1900s develop from nationalism and imperialism? Discuss the debate among allies on the necessity to declare war provoked by the assassination of Archduke Ferdinand. What nations or leaders do you think bear the responsibility for the outbreak of WWI?

Many books could be written on just one of these questions, so this answer does not claim to be comprehensive. The first critical point to be made is on the shift to imperialism. During the middle of the nineteenth century, the last major European nation states, including Italy and Germany, were consolidated into unified entities. This played a major role in expanding their economic power and influence, as they sought to challenge the more established states, France and Britain, for global power and colonies.
After Germany in particular had established a national economy, it began to look beyond its borders for new markets, raw materials, and trading opportunities. By the latter decades of the nineteenth century, the “scramble for Africa” was in full swing, as the European powers competed for control over the resource-rich continent. These factors encouraged the development of alliances. France and Russia, later to be joined by Britain, formed the entente. Germany, meanwhile, had a dual alliance with Austria-Hungary and was seeking to develop its economic and trading interests into the Middle East via the Ottoman Empire. Under these conditions, it was only a matter of time before war broke out.
Britain, which controlled the largest empire in the world, could not accept Germany’s efforts to obtain “a place in the sun.” This was summed up by British diplomat Eyre Crow, who declared in his famous memorandum of January 1907 that Germany was attempting to dominate Europe, and that Britain could not make concessions.
Precisely who was responsible for the war in 1914 is a contentious issue. The German historian Fritz Fischer carried out groundbreaking work in the 1960s to show that planning for war in Berlin was meticulous and the conflict was desired. But an argument can be made that this was true in all countries. After Germany gave Austria-Hungary a blank cheque to confront Serbia, Russia saw an opportunity to expand its power in the Balkans. France could not tolerate a strengthened German neighbor and was bound to Russia in an alliance. Although Britain claimed it entered the war to defend the independence of Belgium, this seems less credible when you consider that it ruled as the colonial power over a huge empire, including India, large swathes of Africa, and even Ireland. None of these countries were free or independent.
The question of imperialism is crucial to an understanding of this period. Lenin’s 1916 work, Imperialism, the Highest Stage of Capitalism, deals with this question from a Marxist perspective. Liberals also took up the question of imperialism, an example of which was the British writer J.A. Hobson’s 1902 work, Imperialism: A Study.
The outbreak of the war in 1914 is also a vast area of study. It should be looked at in connection with a growing frequency of conflicts over the years prior to 1914, such as the series of crises over Morocco, the Balkan wars of 1912–13, and the race for naval supremacy between Britain and Germany. The assassination of Franz Ferdinand and the conflict it triggered did not come out of the blue.
Regarding nationalism, the unifications of Germany and Italy are key topics, as is the turn in France, Germany, and many other countries in the decades before the war to a more aggressive, militarist nationalism.
https://archive.org/details/imperialismastu00goog

https://www.britannica.com/biography/Eyre-Crowe

https://www.marxists.org/archive/lenin/works/1916/imp-hsc/