I read a book when I was a kid in the late 90s, but it maybe wasn't for kids.
A boy gets transfered to another realm and I only remember they had a huge area of glass where some magicians had been fighting and they had used their magic to summon dragons and it went totally bad, all the earth melted to glass.
When the boy later comes home to his world, he sees a news report about new missle system called dragon that is supposed to solve some military problem. Think that was on the last page of the book.
Sorry, that is all I remember.