Why treat them as alternatives? Prove friendliness and then take precautions.

Indeed, that is what we should do. But the danger with biased human thinking is that once people know there are precautions, most of them will start thinking the friendliness proof is not extremely important. The outcome of such thinking may be less safety.

We should make the friendliness proof as seriously as if no other precautions were possible. (And then, we should take the precautions as an extra layer of safety.) In other words, until we have the friendliness proof ready, we probably shouldn't use the precautions in our debates; only exceptionally, like now.