["Philosophy &Public Affairs, EarlyView. ", "\nABSTRACT\nMany of the most pressing moral problems we face involve collective harms generated by large numbers of individually insignificant actions. Unlike triggering cases—where a threshold exists such that a single act could be decisive—non‐triggering cases lack any such sharp cutoff. In these cases, no individual act appears to make a difference to whether harm occurs, and it may be metaphysically indeterminate whether a given aggregate is harmful or whether a marginal contribution plays any causal role at all. I argue that standard approaches to moral responsibility, which rely on difference‐making or expected outcomes, struggle to provide action‐guiding reasons in these contexts. Drawing on the security‐dependence account of causation, I argue that agents have pro tanto moral reasons to refrain from actions that make harm more secure, even when those actions neither determine outcomes nor probabilistically influence them in any straightforward sense. Doing so explains how individual actions can remain morally relevant under conditions of overdetermination and metaphysical indeterminacy.\n"]