No Survivors Please is one strange duck - not really science fiction, more of a political allegory with very, very light Sci-Fi overtones, similar to another film of the era, Planets Against Us, with which NSP shares some marked similarities.
NSP is, if anything, a dark treatise on modern existence, and love without "soul." World leaders and celebrities are taken over by aliens, by being killed and "reborn" - a not-subtle allusion to religious indoctrination - and become cynical, amoral versions of their previous selves (a page taken out of Invasion of the Body Snatchers). As such, this aspect of the film is an overt allusion to the modern world politician as being a soulless, self-serving engine of destruction, even while he pretends to be a helper to society - a not inaccurate description of such career ghouls.
As the main theme of the film is the precarious nature of international harmony, the esteemed United Nations features prominently, and there are some wonderful shots of that magnificent - and woefully maligned - institution. As with the aforementioned Planets Against Us, NSP comes across largely as a meditation on topical issues of the day, existential alienation urban loneliness. The main characters, including our hero, a reporter, all suffer emotional detachment, and a good part of the film deals with the angst suffered by those who wish to reach them emotionally.
In the execution of their plan, the aliens resort to fairly heartless murders, the most gruesome being that of a young woman who is unceremoniously tossed off a high bridge, screaming in terror as she falls to her death.
Yet the finale, in which the alien implants discuss starting a World War in order to teach humans beings how not to wage World War, seems confusing and self-contradictory at best, and in the final analysis it is almost impossible to tell what NSP had in mind. Although it was listed as science fiction in TV Guide listings back in the day, other than the fact of the replicated humans there is nary a Sci-Fi plot point to be found, and unless I blinked, not one special effect in the whole thing. A strange duck indeed, No Survivors Please may work best as a stark, despairing monochrome depiction of modern America as a repository for emotion-free predators working ceaselessly behind the scenes towards our mutual destruction, and as such reflects the current world political climate eerily.
