The global economic cycle starts with an increase in "money" available to loan, usually accompanied by a decreased cost of "money". Then international trade picks up. Then the price of commodities picks up. Then global shipping rates pick up. And shipping rates did pick up, a lot. Well, some global shipping charter rates are now diving.
In the last month or two, iron ore rates from Australia to China are down about 67% to about USD 10/ton. Iron ore rates from Brazil to China are down about 50% to about USD 21/ton.
The US Treasury and Fed, with the significant help of the 51st state of Japan, has created huge amounts of USD (remember, USD can not be created without creating credit / debt, also known as liquidity). A number of times since the early '80s there have been threats of an economic slow down in the US. The treasury and Fed have always responded by creating large amounts of USD to be loaned or spent. This tactic or trick will not work forever as the world has only so much real value to loan the US. That point is for all practical purposes here, although it is the beginning of that point.