"We judge that, in the absence of realistic and successful testing, declaring the system operational -- and any further deployment of GMD components -- would be technically indefensible," the letter said.
In other words they want to kill the program. After all, they just set up a situation for resumption that requires money to happen after demanding that there be no money.
The fact that so many Nobel winners endorse this letter causes it to lose credibility in my eyes, considering the record of Nobel (not to mention the recent Pulitzers) award winners. I like that all of these "Top" scientist remain unnamed; this is probably because none of them are actually top in a field that applies to this issue.