Russia will deliver to China four battalions of 200-kilometer-range S-300PMU2 surface-to-air missiles this summer, the last batch in a series ordered by China. The first batch of four battalions of the same missiles was delivered in July 2007.

Starting in 1993, China received 12 battalions of S-300 SAMs, four of them S-300PMUs and eight S-300PMU1s. This means there are a total of 20 battalions of S-300 SAMs deployed in China. These missiles are expected to play a major role in China's core air defense system.

These missiles now cover the whole of the Chinese coast facing the Taiwan Strait. Positions previously covered by HQ-2 ground-to-air missiles have been upgraded to S-300 launch positions.

In the combat theater centered on the city of Fuzhou in Fujian province, Longtian Airport is armed with S-300s, which are intended to cover the whole northern section of the combat area. The S-300PMU1/2s deployed along the Taiwan Strait are right along the coastline, providing the first line of air defense for the operations of AWACS and bombers behind the front lines.

Since H-6H bombers are armed with long-range YJ-63 air-to-surface missiles, the KJ-200/2000 AWACS and H-6H/Ks outer-line protection is supported by the S-300 SAMs. These land-based SAM systems will provide effective protection against attacks from the air.

The objective of deploying S-300 SAMs at Longtian and Huian Airport is to protect the airports during a confrontation, and provide emergency landing sites for damaged combat aircraft. The mainstay third generation fighter aircraft including Su-27, J-11, Su-30 and J-10A fighters will not directly use these airport facilities due to their long flight ranges.

Originally, there was one S-300 position and one HQ-2 ground-to-air missile position at Longtian Airport. The S-300 position is composed of four launch vehicles and uses 64N6E search radar. This indicates that the ground-to-air missiles deployed at this airport are at least S-300PMU1s, because in the early phase the first batch of these missiles imported from Russia used ST-68UM (36D6) search radar produced by the Ukrainian Iskra Industrial Complex.

One battalion of the PLA Air Force's S-300PMU1 missiles normally uses four launch vehicles. The HQ-2 ground-to-air missile launch positions originally deployed at Longtian Airport are probably being rebuilt at the present time. A standard HQ-2 launch position usually has six launch sites, but currently the position has a layout of four launch sites and is equipped with a new warehouse. This is very likely prepared for the deployment of the S-300s. Nonetheless, the latest Google Earth satellite images show that S-300 missiles have not yet taken up this position.

Huian Airport is located in the north-central section of the Fujian coast directly facing the Taiwan Strait, and S-300s are also deployed at this airport. Besides, S-300 SAM positions have also been built in the Xindian area close to the city of Xiamen, where HQ-2 SAM positions have been upgraded to S-300 positions.

The HQ-2 positions in the Jiaomei area have also been rebuilt into S-300 positions. An analysis of images of the two positions released by Google Earth indicates that S-300 missiles have not yet been deployed here, however. HQ-2 SAMs were originally deployed at Zhengzhou Airport. The structure of the position currently being rebuilt is rather blurry. It is worth watching whether S-300 SAMs will be deployed here in the future.

In sum, there are five S-300 positions and two HQ-2 positions along the Taiwan Strait, the latter two located at Zhengzhou and Shantou Airports, with altogether 20 S-300 launchers. The No.2 Ground-to-Air Missile Brigade is stationed in this area.

S-300 positions are also found under construction in Beijing and Qingdao. The missiles have been sighted at the Zhonghuabu position near Qingdao, indicating this is the newest S-300 position, probably intended for the deployment of the latest S-300PMU2s. The importance of Qingdao lies in that the S-300s deployed here can be used to provide protection for the PLA Navy's No.1 Nuclear Submarine Base currently under expansion.

Almost all the S-300PMU1s are concentrated around Beijing. The No. 5 Ground-to-Air Missile Division was the first air defense unit to receive the S-300 missiles. It deserves close attention whether the No. 6 Ground-to-Air Division has been equipped with, or will receive, S-300 SAMs.

A new HQ-9 ground-to-air missile position has been observed at Fangezhuang, indicating that at least two battalions of HQ-9s are now under operational deployment. The first HQ-9 launch position was discovered at Jiuquan. Different from the S-300 position, the HQ-9 position is rectangular in shape, with eight launch sites. This means that one launch battalion is composed of eight launch vehicles, and the fire control radar is placed in the middle of the rectangular-shaped launch position.

At the outer rim of the launch position, circular roads connect the launch sites to enhance mobility and logistic efficiency. The deployment of HQ-9s in Beijing means that China's air defense capability has improved greatly, with a network that provides multiple-system, long-range and deep air defense. However, observers outside China have little knowledge of the technical parameters of the HQ-9. At least six S-300 SAM positions have been noticed around the Beijing region.

Other S-300 positions have been identified in Dalian and Lushun. This region is given special attention as it occupies a strategically important location; any aerial attacks upon Beijing launched by U.S. forces based on the Korean peninsula would have to go through this region.

Another major city currently protected by S-300 SAMs is of course Shanghai, where the No. 3 Ground-to-Air Missile Brigade is stationed. The Nichung and Minhang S-300 positions to the south of Shanghai are very close to the shore, and are obviously intended to deal with air attacks on Shanghai by Taiwan's tactical air force units in the event of a confrontation.

The 64N6E search radar used by S-300 SAM systems has also been sighted in the area close to Gongjialu, which very likely transmits aerial information data to other S-300 positions deployed in the neighboring area. One S-300 position is found at Liuhe to the north of Shanghai. The whole Shanghai area seems to be under the protection of four S-300 SAM positions.

The layout of the above missile positions reveals to some extent the tactical intentions of the PLA Air Force, that is, to give priority protection to Beijing and the coastal region with its S-300 SAMs. In particular, the air defense network along the coastal region including the Taiwan Strait and Shanghai has been greatly reinforced. A total of 18 S-300 SAM positions have been identified.

After receiving the new batch of four sets of S-300PMU2 missiles this year, and with the deployment of the HQ-9s, it deserves close observation whether China will continue to purchase new S-300 serial SAMs from Russia.

(Andrei Chang is editor in chief of Kanwa Defense Review Monthly, registered in Toronto.)