Joseph Lieberman actually said...

If this regime were to acquire nuclear weapons, it could spark a dangerous arms race in the Middle East.

The right policy for the United States, in my judgment, is thus to stand by the invitation for international discussions.

The United States cannot be passive and do nothing given the grave threat a nuclear-armed Iran would pose for the United States, Israel and ...

What happens when they achieve that capability? Well, of course, for Israel... it represents an existential threat.