Inasmuch as Manoel de Oliveira's films convey what Randal Johnson describes as a cinematic hybridity that illustrates the amorphous nature of representation, No, or the Vain Glory of Command also reflects a temporal hybridity, where time is presented as a conflation of seemingly arbitrary, but integrally connected history. Opening to a long take of a large ancient tree shot from a moving camera platform in the African wilderness, the correlation between enduring image and its representation through a constantly shifting point of view also serves as a contemporary metaphor for Portuguese history itself, where its consequences continue to be re-evaluated through the shifting perspective of an increasingly marginalized legacy. Shot in 1990 as a historical fiction on the waning days of Estado Novo and colonialism under the Salazar regime that crystallized with the Revolution of 1974, the film further incorporates a tertiary, non-fictional chronology, as the soldiers sent to Angola to suppress the insurgency and maintain control of the "overseas provinces" (even as the country faces its own domestic crisis resulting from dissatisfaction with the repressive government) revisit the decisive battles and pivotal events that would shape the course of Portuguese history.

Composed as a series of conversations between drafted history scholar, Lieutenant Cabrita (Luís Miguel Cintra) and members of his brigade, Manuel (Diogo Dória), Salvador (Miguel Guilherme), and Brito (Luís Lucas), and interwoven with re-enactments from watershed events, from the assassination of the great Lusitanian warrior, Viriato (also played by Cintra) that would alter the dynamics of the battle between the Lusitanians and the Romans for the domination of the Iberian peninsula, to the defeat in the Battle of Toro (and subsequent accidental death of Prince Afonso from a horse riding accident that would end the dream of a unified Iberian Empire under one crown, to the disastrous Battle of Alcácer-Kebir that would result in King Sebastian's (Mateus Lorena) disappearance in northern Africa that would setback Portuguese exploration (and consequently, its empire building). It is interesting to note that by juxtaposing history-based fiction with historical non-fiction, Oliveira illustrates the process of mythologization, where history becomes refracted and idealized in times of crisis and upheaval. However, rather than engendering a romanticism for the past glory, Oliveira dismantles the myth of conquest, reframing history as an elusive (and delusive) quest for fleeting victories and unsustainable empires. This mythologization is prefigured in the idiosyncratic inclusion of sea-faring explorers arriving at a Garden of Eden-like paradise populated by nymphs and cherubs, suggesting the intersection between history and myth, and culminates in the symbolic image of King Sebastian emerging from the fog clutching the blade of his sword - a figment of Cabrita's subconscious - that reinforces the human cost of war in the vain pursuit of empires. It is this image of bloodied hands - a symbolism that is also implied in the legend of the Mangled Man who, despite severed hands, continued to hold the kingdom's flag during the Battle of Toro - that is evoked in a physician's dated entry of April 25, 1974 that concludes the film: the implication of the Salazar regime as the end of another failed empire within the sweep of history, bound together by collective sacrifice, inhumanity, delusion, and tragedy.