Sea Lanes Revisited

In an earlier post (Feb 20,2005), I set out a definition of sea lanes. In light of much recent discussion of China, I am reposting that information:

I keep posting about sea lanes. What are these things? Sea lanes are trade routes - almost like highways in the sea, where due to geography, ocean going vessels follow certain paths to avoid island, shallows and other impediments to their travel. They are also generally the most efficient routes to get from Point A to Point B - as close to straight line travel as a ship can accomplish given the number of obstacles in its path.

Of particular interest in recent days are the sea lanes China is working to find ways to protect. As you can see from the following (which just reference crude oil shipments) these lanes are heavily travelled. In the first chart, I have marked U.S. allies in blue (yes, Singapore is oversized) and areas that China is making claims or working to establish relations as red bursts. Note that the red bursts sit athwart the sea lanes. The second chart is from 2004 and you should be able to detect an increase in crude being shipped.

1993 lanes


Chokepoints: Maritime Economic Concerns in Southeast Asia Institute for National Strategic Studies, Washington,D.C. (National Defense University, 1996)
(color and bursts added)

2004 lanes


from Straits, Passages and Chokepoints: A Maritime Petroleum Distribution by Jean-Paul Rodrigue Rodrigue. Similar charts exist for other raw materials, such as metals.

So? Well, as Parapundit put it so well:

Oil is China's Achilles Heel from the standpoint of military strategy. Even if they use their massive economic growth rate to build a much larger blue water navy (and I expect they will do exactly that) it is far easier to deny the use of the oceans to some nation than to protect the sea lanes. On the other hand, even if the US and China clash over Taiwan the US would have a difficult time denying oil to China while still allowing oil to get through to other nations in East Asia. Though conceivably the US could allow tankers with carefully selected crews of known loyalties to go around New Guinea headed toward Japan and South Korea.

China wants to be in a position to defend its trade route/sea lanes and they are taking steps now to do so.

The fact that they are also vital to Japan, South Korea and lots of other countries is problematic not only for the reasons Parapunit points out, but because the potentially impacted countries are being targeted individually in what really is a collective problem. The U.S. is interested for economic and security reasons.

And that's why I keep posting about it.

Update: I note that Wretchard over at Belmont Club is also posting on the significance of sea lanes to China and what it means in terms of Taiwan:

But even if the United States could be persuaded not to intervene in any dispute with Taiwan, China's peculiar geographic vulnerability to maritime disruption means that even Taiwan's small submarine force could pose a major threat. This map from Global Security underscores how vital the South China Sea is to China's economy. Virtually all VLCC traffic to China, Japan and South Korea pass through the Lombok and Malacca Straits. Traffic bound for the cluster of ports (run your mouse along the Chinese coast and the ports will pop up as circles) around Guangdong (Hongkong and related ports) can stop 600 km west-southwest of Taiwan, but traffic bound for the port clusters around Shanghai must pass east of Taiwan, through the Luzon straits before berthing 600 km due north of Taipei -- right past the Bonins -- including Okinawa. Should Taiwan respond to a Chinese threat by deploying its Zwaardvis class diesel electrics along the Bonin littoral, the northern Chinese ports would be blockadaded. Both the Guangdong and Shanghai ports themselves are well within range of the 9,000 nautical mile ranged Taiwanese diesel-electrics.

Here is where some military analysts may have it wrong with their scenarios of a triumphal Chinese descent on a hapless Taiwan.  Taiwanese diesel electrics could respond to mainland saber rattling by taking station to the Bonins northeast of Taiwan and would be far better suited to littoral warfare than the nuclear attack boats Beijing is building. Moreover, any combat between Taiwan and China in this area would be exceedingly dangerous, because it would occur virtually within Japanese territorial waters. China would have to be very careful in naval operations or risk attacking Japanese fleet units by accident. Escorting tanker convoys east of Taiwan and through the Bonins  would be a nightmare. In fact, Taiwanese naval action need only be threatened: any naval confrontation in the South China sea would almost certainly disrupt commercial and oil traffic not only to China, but to Japan and Korea as well. If that were not enough, the Taiwanese subs could head south as well. All Taiwan would need to do is torpedo one large VLCC in the Malacca straits to block it for months...

While I don't agree that the sinking of one VLCC in the Strait of Malacca would result in a long term closure, the rest of his points are well made.

Update2: See also my postChina Builds Up Strategic Sea Lanes here for a discussion of the similar problems faced by China today and Japan at the start of WWII as this map of Japan's conquests shows:

and the two-phase approach as described by China Defence Today

The PLAN's evolving strategy has been described in terms of two distinct phases. The strategy's first phase is for the PLAN to develop a "green water active defence strategy" capability. This "green water" generally is described as being encompassed within an arc swung from Vladivostok to the north, to the Strait of Malacca to the south, and out to the "first island chain" (Aleutians, Kuriles, Ryukyus, Taiwan, Philippines, and Greater Sunda islands) to the east. Analysts have assessed that the PLAN is likely to attain this green water capability early in the 21st century. Open-source writings also suggest that the PLAN intends to develop a capability to operate in the "second island chain" (Bonins, Guam, Marianas, and Palau islands) by the mid-21st century. In the future, the PLAN also may expand its operations to bases in Myanmar, Burma. These bases will provide the PLAN with direct access to the Strait of Malacca and the Bay of Bengal.

Wretchard has now posted his conclusion with reference to a threat to Taiwan:

Taiwan is the secondary mission. Keeping China's access to energy is the primary mission.

That's probably close to right.