On his own soil and aslong as he's in office, he's own people will claim plausible deniability anyway, wether he admits it or not. Again quite irrelevant. The main reason he wont, is so he can stack up on temporary allies. Like Greece for example, who has been really trying to woo the East, since Europe hates it now. If he admitted it, Greeces own people would force their government to cease communications and for a really solid reason of being friends with massmurderers. Right now, since there really isnt a solid reason(depends who you ask) and everything is plausible, the governments who support his reqime, get less foreign hate and internal hate.