A nasty little article who can be found in any army anywhere. This man is Corporal Nobby Nobbs without any of Nobby's redeeming qualities. This is the sort of junior NCO who is a bully to those under him and a toady to those above him. Like Nobby he will steal whatever is not actually nailed down, but unlike Nobby he has no sense of loyalty to his mates nor any respect for those senior ranks who to Nobby deserve - and get - respect. He can put on a sham of respect, but at bottom the only person Strappi has loyalty to is himself.
In the sort of army where the soldiers are encouraged to "report" each other's failings and possible disloyalties, the likes of Strappi will flourish and will think nothing of turning in "traitors" in exchange for a nice cosy posting well away from the front line. If it involves being entrusted with green recruit soldiers to bully and beat and mistreat, then so much the better. Strappi is a man who is everything with his two stripes of office and nothing without them. Like Mayonnaise Quirke, he will attack weakness without mercy but recoil from strength, as Polly Perks discovers. Perks becomes his bete noir and eventual downfall...
In Roundworld, the sadistic training NCO or commissioned officer who abuses their power is not uncommon, especially in the past. In some countries, they are exceptional; in others, they are integral to the military hiearchy.
The most famous example (and probably direct inspiration for Strappi) is present in the anti-war novel "All Quiet on the Western Front". Upon their arrival at the training camp, the protagonist and his fellow recruits are relentlessly drilled by Corporal Himmelstoss, who delights in forcing the recruits to crawl in the mud, and to repeatedly march and counter-march back and forth. Like Strappi, Himmelstoss is a bully and a coward, who uses his authority to intimidate those below him, and clings to his training position as a way of avoiding the front lines. The ressemblance ends there however, as Himmelstoss ultimately redeems his earlier behaviour.