Nighthawks is a 1981 thriller film starring Sylvester Stallone, Billy Dee Williams, Lindsay Wagner, Persis Khambatta, Nigel Davenport and Rutger Hauer. It was directed by Bruce Malmuth. The story revolves around the lives of two NYPD police detectives, Det. Sgt. Deke DaSilva (Sylvester Stallone) and Det. Sgt. Matthew Fox (Billy Dee Williams) who work undercover, and a terrorist Heymar Reinhardt, alias Wulfgar (Rutger Hauer).

After having their undercover detail compromised by two uniformed officers, DaSilva and Fox are informed that they have been transferred from the Street Crime Unit and into a special Federal-State Unit. After a touchy moment with their superior, Lieutenant Munafo (Joe Spinell), they discover that their transfer orders came from the commissioner, whom had received the orders from Washington D.C.. The fact that the two detectives served in Vietnam also play into this, making them two of the highest recommended candidates for the special unit. Anti-Terrorist Action Command (A.T.A.C.) is assembled by INTERPOL British Counter-terrorist specialist Peter Hartman (Nigel Davenport).

Hartman believes Wulfgar will come to the U.S. next primarily for the press coverage. Hartman schools DaSilva, Fox and a specially selected team of New York police on Wulfgar, Shakka, and terrorism in general. But the ‘shoot-to-kill’ policy that Hartman encourages doesn’t go down well with DeSilva who didn’t join the force to kill anyone.

Wulfgar announces his presence in New York by bombing several locations in the Wall Street area. Eventually DaSilva comes face to face with Wulfgar. Wulfgar now has his sights set on DaSilva as well as his other targets. DeSilva can now only wait for Wulfgar to make his next move.

Summary via Wikipedia.