Another easy thing you can do, which I did several years ago, is download Kiwix onto your phone, which allows you to save offline versions of references such as Wikipedia, WikiHow, and way, way more. Then also buy a solar-powered or hand-crank USB charger (often built into disaster radios such as this one which I purchased).
For extra credit, store this data on an old phone you no longer use, and keep that and the disaster radio in a Faraday bag.
It varies, but most treaties are not backed up by force (by which I assume we're referring to inter-state armed conflict). They're often backed up by the possibility of mutual tit-for-tat defection or economic sanction, among other possibilities.
Another easy thing you can do, which I did several years ago, is download Kiwix onto your phone, which allows you to save offline versions of references such as Wikipedia, WikiHow, and way, way more. Then also buy a solar-powered or hand-crank USB charger (often built into disaster radios such as this one which I purchased).
For extra credit, store this data on an old phone you no longer use, and keep that and the disaster radio in a Faraday bag.