Whole thing is confidence game, you are right that no one knows when another Nixon shock will come. Presently we have open capital market with rising debt only option they have is YCC (Yield curve control) like before. That time there was no open FX market, rationing, shortage of goods, I don't think capital market were open like now with funds moving instantly.
Next shock will be capital control, YCC, price control and devalue Dollar. We are not there yet. Same as they done during the war and after the WW2. That time FX was fix this time it will stay open. Everyone will get paid back in devalued Butt wipes. Gold will run like hell just like 1970.
Another option is to make Fed Money legal tender. Last page
There has been so much inflow into stocks and bond due to Zero returns. Only place for savers is in the Fed casino. How much spare cash will they have for the Casino with rising Inflation? Not Much
You know once you are loaded up in risky assets there is no way out unless it keeps going up. If it stops and head south. capital goes down also can't leverage your capital. margin call if it's leverage.
That what's happening in Gold. other assets will do the same.
I am watching USD for where market will head. Strong USD is bad for the market for now. Weakness means smart people are looking for a different out come.