Wouldn't that be simply just through govt T-bills which have almost no risk.
To be honest many things are fairly safe in the long run unless you get completely burned in the short run.
Nothing you can really do about that. I would just do T-bills
To be honest, I expect some big changes in the government in the upcoming decades, so even that may not be a SURE bet... in terms of value.
All investments, ALL of them have some kind of risk.