I've read the ETA's communicate in a Colombian newspaper and...
Well, it IS a good step that they doing there, but at the same time it puts ETA in a very confortable position: if the Spanish and French goverments say no way, we will keep our security policy, ETA could easily play the "victim" game...: "You see, those evil and imperialist goverments that don't recognize the democratic steps done by our organization, bla-bla-bla... so we see ourselves forced to return to our arms".
Perhaps it's just my pesimitic and very Colombian way to see things (FARC and all the bunch of armed groups we have in our country have made similar "steps towards the peace" in the past... and well, the situation is still bad), but I still wish luck to you.
Perhaps you are smarter and can finish your problems in a more civilized way than us.