Neutral States must abstain from supporting a party to a conflict with military equipment and assistance. This core aspect of the law of neutrality has neither changed with the adoption of the UN Chater in 1945 nor with the brutal Russian aggression against Ukraine. That said, by reviewing the changes to neutrality law over time, this article finds plausible reasons to believe that neutrality has – for better or worse –, over time, become optional for the vast majority of States who can today opt to be non-belligerent States, i.e. States that are neither neutral, nor parties to the armed conflict. All States have to cooperate to bring to an end serious violations of international law, including humanitarian law, and this duty of cooperation abolished “sitting-still-neutrality”, but it does not render neutrality law moot. This reading of “optional but not qualified” neutrality maintains intact the core idea of neutrality to abstain in military matters. I argue that views of “obsolete” or “qualified” neutrality are not new at all but depart from well-accepted rules of legal interpretation and raise concerns about double-standards. Viewing neutrality as optional but unqualifiable offers greater conceptual clarity, is more honest than alternative views and comes with advantages for humanitarian action.