Creationism itself is zero treat, scientifically. But the tactics of creationists -- whether trying to stifle teaching of evolution, or failing in that, trying to compel the teaching of spiritualism as science, is indeed a thread. It's a threat to all of Western Civilization, which is built on rationality. Such tactics would be opposed if they were employed by astrologers attacking astronomy, phlogiston wizards attacking chemistry, etc. Not because astrology or the phlogiston theory are scientific threats, but because the Luddites are on the march.
And what would you do with Dawkins? How does one not tolerate the free expression by a scientist on any topic he wants to talk about?
(Spell checkers can't catch everything.)
To tolerate Dawkins means to put up with his free expression without contradiction. If the Royal Society is going to respond to the unscientific claims of the creationists, it should also respond to the unscientific claims of Dawkins.