Thanks, everyone, for your thoughts.
Here is my own model of things, which is really Harry Browne's idea. The US dollar is the number one most popular money in the world. Gold is the number two most popular money. When there is crisis and uncertainty, yes, people want to hold more money. They feel vulnerable and want to be more liquid, they want more in their pocket. That does not necessarily mean that gold goes up. It does probably mean that the dollar goes up. Gold may or may not go up.
So, there is no direct and necessary link between a crisis and gold prices going up. E.g.: 9/11 happened, and gold prices did not go up.
However, when there is significant price inflation in the US, as in 5, 6, 7% or higher, then people all over the world start to get antsy about the dollar. They were holding it for safety, and with price inflation they are losing that. So, they start to get out of the dollar and instead hold the number two worldwide money: gold.
So there is a direct causal link between gold and price inflation. There is also the well-known link between monetary inflation and gold (and all commodities, and all products, really). When the Fed inflates the money supply, then, all else equal, prices of everything will go up eventually, and that includes the price of gold. But that can be a very delayed reaction. It's uncertain how long it will take for monetary inflation to manifest in the economy as price inflation. But because gold is used worldwide as a money (not for many day-to-day transactions, but as a store of value), there is that additional factor which will make it tend to go up when its competitor, the dollar, goes down.
The dollar and gold are both competing for market share as money. As things are, the dollar has many, many advantages over gold for most people and so it is number one. But if the dollar's downsides suddenly increase -- as in the situation of a major inflationary period (see the 1970s) -- gold will look better in comparison and some people will convert to using gold for their savings.
As eric_cartman said, the dollar is still strong. That is, even though there's been lots of monetary inflation, there has been no serious price inflation yet. Until there is, gold's future is uncertain. Once there is, then gold will have a strong tendency to go up, and go up a lot.
We do not know when, or even if, this will occur.
Thoughts?