A review of this production in the Times notes:
The setting is Adelaide in the eighteen seventies. The placid community there are becoming slightly inflamed by the whiff of jingoism from the home country. The hero–a schoolmaster–is firmly turned down as a suitor for the hand of a colonel's daughter. No: education must give way to defence. The colonel's big chance comes when a Russian gunboat is rumoured to be lurking round the coast; supported by a politician, a newspaper editor, and a building contractor he sets about whipping up public enthusiasm for a standing army.
'The solitary gunboat is magnified into a whole flotilla, and slogans such as "Arm for peace and prosperity" begin to engage the community in industrious preparation which sweeps the financial speculators towards wealth and the colonel towards an eminence far above his position at the head of a Saturday afternoon cadet force.
'There is no savagery in this satire; and what follows is pure farce. The alarm sounds one night and the army march off to do battle, only to find that they have been mistakenly alerted and that during their absence they have been legislated out of existence.'
Source:
'Night of the Ding-Dong', The Times, 3 February 1958, p.12.