Major Buy in the Materials Sector?

The real money in trading is made when assets get dirt cheap and have a value backstop. That's when you can really load the boat with relatively low risk. (Note: I 'm talking about real risk here, not day to day volatility. Vol normally goes up in these situations.) I've mentioned a few of these on this blog: rhodium, vanadium, nickel. I think we are six months or so away from a major bottom in the entire materials sector. Here's why.
There are two basic factors that determine the long term commodity cycle. On the demand side is world economic growth, particularly in the commodity-intensive developing countries. On the supply side is the amount of capital going into investment in commodity capacity. A lot of commodity capacity gets used up in normal operations (think of a mine's depletion) so capital is necessary on a sustaining basis.
We have been in a state of low investment for several years now. Most of this is due to the over-investment in the '08 - '13 period. But time marches on, and the lead time for new mines, oilfields and agricultural plantations is long. So there are many materials which will not see capacity increases, and perhaps declines, for years.
The demand side is more interesting. Many nations/regions follow a natural commodity demand cycle. As they develop and put infrastructure, consumer durables and structures in place, they become commodity-intensive. Then as development continues, the service sector, which uses few commodities, rises to the fore. The US/EU/Japan are in that situation now. The growth in commodity demand comes from emerging markets, mostly Asia and mostly China (for now).
The key to Asian development over the last 50 years has been to start with the export sector. For various reasons, that mostly means exporting to the US. Now economic theory tells us that the creation of a new pool of low-wage workers in Asia will help workers in Asia and capitalists in the US. It will hurt workers in the US. That is pretty much what happened. The failure to spread the benefits of globalism is one of the US's great economic mistakes.
Now we have a reaction. Regardless of what you think of Trump, he is making an effort to protect US workers. This has wide political support, even among Democrats. So I'll bet that this is going to be a long lasting issue. I'll bet that the US trade deficit will decline.
Will this lead to lower growth in emerging markets? The world's stock markets certainly think so. I do too. Basically, it means that the new driver of growth will not be exports to the US, but borrowing from China. This is not as strong a force.
OK, how long will it take for the markets to discount this. Not much I think. My guess is that the imposition of widespread tariffs on China will be a watershed. This will happen over the next six months or so. I would expect to see some commodities fall substantially when this happens.
At that point we have our buy. Remember, the world economy will not decline. It will just have a growth slowdown in the commodity-intensive regions. Meanwhile, the falloff in productive capacity will continue. I do not anticipate a deflation, so cost of production will provide a low risk floor.
That's what I think. Be interested in you opinions on this.