Monday, August 01, 2011

Refresher: World Trade Route Chokepoints

Every now and then it's a good idea to get back to basics and refresh ourselves on basic principles. In this post, I revisit one of the reasons why we have a navy and why navies are important. "Revisit" because I have done this before Sea Lines of Communication or Sea Lanes .

Closely tied to sea lines of communication are "chokepoints" - and there is no better illustration of these vital places on the planet than this article from the U.S. Energy Information Agency in its look at trade route "tight places" - with an emphasis on oil - at World Oil Transit Chokepoints:
World oil transit chokepoints are a critical part of global energy security. About half of the world s oil production moves on maritime routes.
Chokepoints are narrow channels along widely used global sea routes, some so narrow that restrictions are placed on the size of vessel that can navigate through them. They are a critical part of global energy security due to the high volume of oil traded through their narrow straits.
Blue arrows point to chokepoints
In 2009, total world oil production amounted to approximately 84 million barrels per day (bbl/d), and about one-half was moved by tankers on fixed maritime routes. With the onset of the global economic downturn that began in mid-2008, world oil demand declined, and along with it the volumes of oil shipped to markets, both via pipelines and along maritime routes such as these chokepoints. By volume of oil transit, the Strait of Hormuz leading out of the Persian Gulf and the Strait of Malacca linking the Indian and Pacific Oceans are two of the world s most strategic chokepoints.
For more fun reading about chokepoints, see Chokepoints: Maritime Economic Concerns in Southeast Asia (National Defense University (pdf)) which is about 15 years old (but then it's not like the chokepoints move around much, it it?), from which come another couple of illustrations of chokepoints and the flow of commerce.

A "SLOC" is a "Sea Line of Communication" - and a vital thing to keep open in time of war and peace. As you might imagine, sealing off "chokepoints" on a SLOC pretty much puts that SLOC out of use.

Now, suppose you wanted to cut off the flow of oil to Japan - where would you place submarines or ships or aircraft to impose that embargo with the least expenditure of equipment and personnel? Could it be done solely by shore bases? By aircraft?

How about Somali pirates - what key SLOCs and chokepoints can they interfere with? See Where the Somali Pirates Operate and Why, where I put this up:
That's an overlay of shipping lane usage and pirate attacks. You should note that most of the attacks occur as ships leave one chokepoint and are en route to another. This overlay was done in February 2011. A more current version, which I may get to soon, will show an increasing number of attacks around the Bab el Mandeb at the lower end of the Red Sea.

There are alternatives to the Red Sea/Suez Canal route - but they are longer.  See below for a graphic illustration of that point which I stole liberated from someone who should get credit for it.

Should the Southeast Asia chokepoints become closed, there are alternatives for Japan, too, like sending ships on routes to take them across the sometimes ice free Arctic route (see here) or sending ships down below Australia and out into the Pacific. Money and time, though, are both eaten up in using alternate routes.

Better to keep chokepoints and SLOCs open.


That's why we have a Navy.


  1. Rather than oil for Japan, think oil for China. Very bad news for them.

  2. mandb7:12 AM

    As you say, the choke points don't change but it would be interesting to see any change in the maritime traffic flow since around 2006 when the Somali Basin piracy got started. The traffic flow charts available are all dated with a major sealane just off the Somali coast - one that is certainly not there today. Equally the routes taken to the Cape from other locations will have altered dramatically.