Mr Krabs canonically served in the navy and fought in a war but we know nothing about that
if we go by his drivers lisence
krabs was born in 1942. the youngest he could have possibly been to serve in the military is 18 which he wasnt until 1960. bikini bottom uses US currency so we can safely say he lives in united states territory.
we can safely deduce krabs fought in vietnam
thanks, tumblr
He was also born towards the end of the great depression which would explain his understanding the value of a dollar. After what his parents went through, he was probably taught to always save as much as he can. It would also explain his distrust of banks considering banks were one of the things that lead to the great depression that his mother would have lived through.