Didn't we used to do this during the Cold War when the MAD Doctrine was the rule in order not to inadvertantly incite a retaliatory attack?
Yes. The Soviets were even notified, shortly before the launch, of the Minuteman III ICBM I helped launch out at Vandenberg AFB back in the 80s.
Even then we had to hold for quite some time because a Soviet trawler and a sub were spotted in the downrange safety corridor and had to be chased out.