In the picture below there are stacks and stacks of swords in the Zlatoust Armory in Zlatoust, Russia. This picture was taken in 1910, after the treaty ending the Russo-Japanese War. These two topics are only slightly related as I found this picture and then embarked on a quest to learn about the Imperial Russian Army around the turn of the century. I ended up learning more than I ever had before about the Russo-Japanese War and what it caused.
The Russo-Japanese War was a coming out party for one empire and the beginning of the end for another. At the start of the conflict Japanese victory would have seemed somewhat ridiculous, but by the end it was the Imperial Russian Military that embarrassed itself.
The war began in 1905 and pitted two imperial powers bent on expansion against each other. The outcome of this war changed the fate of both nations, which in turn changed the fabric of the international community.
For the Japanese Empire, victory in this conflict proved that they could be successful on the world stage and maybe, one day, join the ranks of world powers. For the Russians this war was quite a different story. There were many significant battles (political, military, and diplomatic) that were fought in this war, but the most important thing this war did was further weaken the Russian monarchy. Losing to the upstart Japan helped cause the Russian Revolution of 1905. This revolution highlighted the labor and class issues in Russian society which continued to be prevalent until the overthrow of the monarchy by the Bolsheviks.
In the context of this class the Russo-Japanese War is important because it was one of the triggers of the Russian revolutionary period. A good resource for understanding this war in a global context can be found here.