The news is bristling with "reactions" to David Cameron's speech. It should be bristeling with "responses".
If you burn yourself on the stove, you react by pulling away and saying something descriptive. That's a reaction. To me, a reaction is not thought through, it's a gut instinct immediate and spontaneous thing. A reponse is measured, thought through and logical.
No politician is going to give his "reaction" on TV. Everyone of them is responding.
My reaction to our "in out" referendum being promised us by the white man who speaks with forked tongue is - " Yes mate, but you promised us that before!" and "I don't believe a word you are saying - taurus excretum, cerebrum vice!"