Yes, holding gold/silver as well as Bitcoin and perhaps one or two of the other cryptos with large market cap, such as Ethereum, Dash, or Litecoin are about as good as it gets in terms of financial insurance. Maybe a bit of cash on hand too for emergencies.
Since war and revolution often accompany economic crises, it is also a wise idea, if you can manage it, to have either a homestead in the country and if possible a 2nd passport or residence in another country. People often forget about that part. Apparently at the end of WWII there was unclaimed money and gold in Swiss vaults sent there by Jews who were smart enough to get their valuables out, but unfortunately didn't act in time to get themselves out. I know this is tough to think about but it's important. There are also places that have many US and Canadian expats such as Panama, Ecuador, where the cost of living is much cheaper so even if there is no revolution or war, these are places where peoples' retirement funds may stretch a lot further, affording them a better standard of living. Puerto Rico is another option, although in my opinion it's too close for comfort to the US, but it may work out great for some people.