Putting a question mark at the end of a statement doesn’t make it a question - except in the case of a rhetorical question.
The question would, presumably, have been:
”But will buying another fighter, be it European or American, will likely bring new economic benefits to Canada, not adversely effecting Canada's existing F-35 partnership?”
To which the answer is obviously yes - but leaves open whether the end result will be more or less advantageous.