You’d think possibly that Japan would be interested in such a system?
Russia tested their system today. The goal of the Bush administration is to unite the entire continent of North America and protect our joint borders. It's a good plan that needs to get off the ground soon (no pun intended).
I believe that Japan has already signed on.
I believe that their planning number for contributing to this project is on the order of $10 billion over some number of years, but it has been a while since I looked, and I could be way off.