Sentence:  Our attitude was that, to put it briefly, our presence there [in South Africa] was legal but <WSD>illegitimate</WSD>. We had an abstract right to be there, a birthright, but the basis of that right was fraudulent. Our presence was grounded in a crime, namely colonial conquest, perpetuated by apartheid. 
Meaning of the word marked with <WSD> tags:  Not conforming to known principles, or established or accepted rules or standards.