I believe that's just because they have not yet found the issue or issues that move them. That doesn't mean they won't find it though.

The public, ... has not until recently found this to be a compelling issue.

We have not found it necessary to make a major move to SIP.

The matter has not yet been resolved. New Zealand clearly have an issue with Zimbabwe.

It's hard to characterize negotiations, but there are issues that we have not agreed on. We're just going to move ahead and see if we can reach an agreement. If not, we'll analyze our options and move forward.

I believe that all these technical issues, although perhaps more extensive than NASA has as yet acknowledged, are all solvable,