The negotiations to revive the Iran nuclear deal have hit the “pause” button following last-minute demands from Russia that threw new obstacles into the talks shortly before the finish line. “A pause in Vienna talks is needed, due to external factors,” EU foreign policy chief Josep Borrell tweeted on Friday, adding that “a final text is essentially ready and on the table.” Russia demanded guarantees a week ago that Western sanctions related to the invasion of Ukraine would not hamper economic and military relations between Iran and Russia. The United States and European countries have rejected…