I don't know. To create a climate where this level of ethnic cleansing is even considered an option would require a rather different historical path to OTL. Certainly the Dominions would be concerned, though they're at far greater distances and have other concerns. I could see protests but there's not a lot else they could do.True, however he would have other means, for example the Dominions, which came into play in OTL during the War, Smuts played a not insignificant role. Would the UK follow through if the Dominions are against this as well as the King?