Chauvinism IMHO isn't that insulting, in Dutch it means exaggerated patriotism (and in general is used to mock that); though apparently in English it also has some other connotations, so maybe stating some seem very patriotic would have been better in hindsight.
Controlling Indonesia and/or Argentina will require resources to control, sure you gain some in the process, not to mention there are only so many British people (or any other European people for that matter) to begin with. With everyone overseas, who will do the work back home?
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Now you're just being deliberately silly. The number of Brits working and soldiering in the Empire (the non-white bits) was always pretty tiny compared to the total population of Britain.
And as to Chauvinist:
chau·vin·ist
ˈSHōvənəst/
noun
noun: chauvinist; plural noun: chauvinists
1.
a person displaying aggressive or exaggerated patriotism.
a person displaying excessive or prejudiced loyalty or support for a particular cause, group, or gender.
"what a male chauvinist that man is"
synonyms: sexist, bigot, antifeminist, misogynist, woman-hater, hater; informalmale chauvinist pig
"he's a chauvinist"
adjective
adjective: chauvinist
1.
showing or relating to excessive or prejudiced loyalty or support for a particular group or cause.
"a chauvinist slur"
synonyms: jingoistic, chauvinistic, excessively patriotic, excessively nationalistic, flag-waving, xenophobic, racist, racialist, ethnocentric; bigoted, sexist, male chauvinist, antifeminist, misogynist, woman-hating