The movie was released on October 18th 1973, during Yom Kippur War between Israel and Arab countries. That very day, the press attaché's wife hijacked a plane to prevent the movie from being released, claiming that the movie was pro-Israeli. She eventually was shot by police marksmen.
The final scene was filmed at Les Invalides in Paris, which is in fact a military hospital and museum. You can even see the tomb of Napoleon, which is part of the complex in the background (It is the building with the dome). There is a chapel in the complex where people can get married.
The helicopter in the final scene wears the registration F-BUFB. Built in 1973, this Sud-Aviation SA341G Gazelle now flies in Italy as I-LDAV. When the movie was filmed, the helicopter was more or less brand-new.