Was anything accomplished at the end of World War One?

You mean after the victory? There were only negative accomplishments. The Treaty of Versailles just about ensured a round 2 being the main one. You might look at the dissolution of the Austro-Hungarian and Ottoman Empires as positives. Poland was also created, or rather recreated. The Baltic states. These are all positive accomplishments, I suppose. If it weren't for the harshness of that treaty it would have been something great coming from something truly awful. But the short sighted French, and to a lesser extent the UK, let the opportunity to fix up a peace that could last slip away.

Empires were destroyed and lots of ethnic groups in Central Europe and the Middle East got their own countries (more or less). And the Allies gave China the shaft, giving rise to the May Fourth Movement and arguably predisposing a lot of people in China into supporting the Communists later on.