Negative security assurances (NSA) were conceived as a quid pro quo for the renunciation of nuclear weapons by non-nuclear-weapon states under the 1968 Nuclear Non-Proliferation Treaty (NPT). They are called “negative” because they amount to a non-use obligation. However, NSA have never been a decisive incentive to join the Treaty. Economic interests, in particular the need to engage in peaceful uses of nuclear energy, played a more important role. Argentina and Brazil would have probably not given up their nuclear-weapon aspirations, had they not feared to be deprived of fuel for their civilian nuclear reactors. With the passage of time, the link between the NSA and the NPT has weakened, practically to the point of non-existence. India, Pakistan or Israel—the three holdouts from the NPT - would certainly not bargain away their nuclear posture for a great-powers' pledge not to use nuclear weapons against them. Nor was North Korea deterred from leaving the NPT; it will not rejoin it in exchange for a mere promise of non-aggression with nuclear weapons. All this means that restrictions or a prohibition on the employment of nuclear weapons may now be treated as potential arms control measures and be negotiated by all states, regardless of their association with the NPT. According to the doctrine of belligerent reprisals, a ban on use does not exclude retaliation. Countries possessing nuclear weapons would, in fact, be committed only to no first use.