But to defend the notion of individual_rights against the charge of meaninglessness, the notion of third-party interventions and fourth-party allowances of those interventions, seems to me to coherently cash out what is asserted when we assert that an individual_right exists. To assert that someone has a right to keep their wallet, is to assert that third parties should help them keep it, and that fourth parties should applaud those who thus help.

This perspective does make a good deal of what is said about individual_rights into nonsense. "Everyone has a right to be free from starvation!" Um, who are you talking to? Nature?

Why such an uncharitable interpretation, particularly when the more plausible unpacking is exactly the one you used in the previous sentence? "To assert that someone has a right to be free from starvation, is to assert that third parties should help them avoid starvation, and that fourth parties should applaud those who thus help." That doesn't sound nonsensical or even incorrect. It certainly doesn't require that you imagine yourself convincing Nature to stop starving people, just as you can say "this potential mugging victim has the right to keep their wallet" without requiring that it be possible to convince the mugger that they shouldn't take the muggee's wallet; even if the mugger is a sociopath or a robot or an alien who couldn't even conceivably be convinced by a moral argument, that would seem to be irrelevant to any argument that third parties should help the victim keep their wallet, and that fourth parties should applaud those who help.