I don't know about a world government - the differences between cultures is still too vast, even among the developed nations, for that to be practical - but I can easily see a world "shrug" if and when one or several nations finally decide to permanently remove that melanoma and its metastases from the globe.
yeah, I don't think it will be too successful ... but I think there will eventually be international anti-terror squads ... very possible ... I think you're correct about the shrug ... few will shed a tear when it happens