How Cargo Travels Through the Shipping System 
I may be obsessing about this Port security issue, but then I am intimately involved with it on a daily-basis. I hope some of these postings will give some insight into the issues involved.
At some point, almost all the world’s Goods pass through a Port. This graphic follows a hypothetical example shipment. If you think that the economic shock from the 9-11 airport shutdown was bad, let’s hope we never have to experience the effects of a similiar halt in Port traffic.