This is based on the project Alicization arc of the SAO Light Novels. Alicization was an attempt to create AI Soldiers. They borrowed tech from the USA, but they gave them obsolete tech instead of working together. (USA trolling! 'Murica!)  Instead they made their own thing with the help of a company. Instead of making soldiers, they made a peaceful Utopia. the rest you can read on the wiki: 

http://swordartonline.wikia.com/wiki/Project_Alicization

My idea is the US sees this idea and tries to recreate it. They work with Japan this time to connect the servers of Alicization. You are a test subject. A human put into it to test it. 

Welcome to the Underworld!

((Note, I need someone more familiar with this to clear any errors I have made. Thanks! You can Co-GM!))