Your teacher may have just jumped straight straight into the The Great War (WWI). But there were definitely some shifting power dynamics going on prior to 1914--the start of the The War. Thanks to industrialization and overseas colonies, most of the Western Hemisphere - Great Britain, France, and the Netherlands, for example - is dominating the global political order. Old friends such as major land empires (Ottomans, Austria-Hungary, Russian Empire, and the Qing Dynasty later on) were replaced by new rising powers like Japan (post-Meiji Restoration) and the US (recently acquiring the Philippines, Puerto Rico, and Guam). However, although World War I exacerbated problems around the world at the turn of the century (especially in Russia and the Ottoman Empire), but it’s worth a look at the four 'hot-spots' in the world prior to the Great War. So, for the sake of efficiency we will focus on Mexico, Russia, the Ottomans, and the Qing dynasty in China.