It's useful to know the silver reserves of central banks at one time in history. This is a FRB Bulletin from 1923. At one time, say up until the early 1960s the US Treasury held as much as 4 BILLION ounces, as I recall. Now, the Treasury is without any = ZERO! It cost us every last ounce to try and stem the run on the dollar. Nationalizing of mines is always a distinct possibility - maybe even a likelihood - with socialist governments building empires by warring, so if you're leveraged with miners, be CERTAIN to backup with suitable physicals, such as bullion coins, "junk" pre-1964 US coins, circulated silver dollars, but hold NO BARS!
Had our government not reneged on its promise of redeemability, today this silver certificate of 1923 would need to be stated as $32 to be redeemable in thirty-two silver dollars! Pause for a moment to think of all those who've lost their retirement savings by saving paper instead of coin. Will you be one of them?