China has forged closer ties with Central Asian states on its northwestern border in recent years. The region hosts Beijing's major concerns: energy security, territorial integrity and terrorism. China is flexing its economic muscle to exert new diplomatic influence.

During an August meeting in Beijing, China, Russia, Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan agreed to work toward economic integration in 20-years time.

The agreement, an initiative under the fairly new Shanghai Cooperation Organization, marks another milestone in the deepening relations between these neighboring countries.

It also highlights China's growing commitment in the oil-rich region, a push begun in the 1990s after the collapse of the Soviet Union.

Some analysts say Central Asia has become the next most important front for China after East Asia and the Taiwan Strait.

Niklas Swanstrom heads the Silk Road Studies program at Uppsala University in Sweden and is currently a visiting professor at China's Foreign Affairs University. He says Chinese expansion in Central Asia is a result of domestic priorities.

"This is partly because of three reasons: One is oil and gas, which China needs for economic development, another is trade especially in Chinese western provinces and thirdly, security, primarily the Uighur movement in Xinjiang," he notes.

One of Beijing's top security concerns is the threat from the restive western Xinjiang region. Xinjiang is home to Uighur Muslims, a Turkic minority group, and some ethnic Kazakhs, Kyrgyz and Tajiks. In the 1990s, a spate of bombings and unrest were blamed on Uighur separatists, whom China suspected were getting support from across the border.

The Shanghai Cooperation Organization, established in June 2001, has become China's main diplomatic tool to counter what it identified as the region's top dangers: cross-border terrorism, religious extremism and separatism.

The SCO evolved from the expanded dialogue between Russia and China in the early 1990s to deal with border demarcation and arms reduction issues.

Beijing urged its neighbors to address their own separatist movements and Islamic militancy to avoid a spill-over into China. It also funneled money to aid in their economic transition from Communist Soviet states to newly independent entities.

Since 2001, SCO members have held military exercises and established a counter-terrorism center in Uzbekistan.

Analysts say the anti-terrorism cooperation and increased investments have been successful in reducing the threat from the Uighur movement.

Li Nan is a Chinese security expert at the Institute of Defense and Strategic Studies in Singapore.

"It's very difficult for these groups to become highly proactive in their activities. They can't find safe haven across the border (or) within the border," says Mr. Nan.

Meanwhile, Chinese investments in the strategic oil and gas sector in Central Asia are to help meet growing energy demands as well as develop its impoverished western periphery and avert serious economic unrest.

China's biggest investment in Central Asia is a multi-billion dollar 3000 kilometer pipeline to pump 20 million tons of Kazakh crude oil to western China.

Commercial ties between China and Central Asia go back to the ancient Silk Road that ran between Europe and the Far East. Today, the Silk Road is being revived largely with Chinese money. Xinjiang now has 17 land crossings to Central Asia. Chinese goods are easily found in markets across the region and Beijing has offered millions of dollars in credit to these nations to buy more Chinese products.

Mr. Swanstrom says that Chinese supremacy in the region was almost inevitable until the September 11 attacks on the United States.

"Before September 11, it was almost evident that China would become the most powerful state in the region, fairly quickly," he explains. "It was because the Russians have their own economic issues to deal with and they can't really assist in the economic development of Central Asia to the same extent that China can do. But after September 11 the US has engaged more and more in the region due to political reasons, i.e. terrorists. So now the Chinese's political take over of the region has really been delayed."

The war on terrorism in Afghanistan in 2001 brought U.S. military troops to Uzbekistan and Kyrgyzstan. Analysts say China began to worry about U.S. encirclement.

"Consider the situation surrounding China," said Akihiro Iwashita, a professor at Japan's Hokkaido University Slavic Research Center. "East, it's covered by the U.S.-Japan alliance. South, it's ASEAN. On the west, India is a former foe of China. So in this sense the Russian federation and Central Asia is a buffer zone, but now the United States is progressing in this vacuum."

Analysts warn of a future great power collision in the region among the United States, China and Central Asia's traditional power, Russia.

Mr. Swanstrom says future conflict cannot be ruled out.

"Nobody prioritizes Central Asia, but everybody wants to keep out all other states," he adds. "Internal instability and arrogance from external powers is not a good equation."

Yuan Jing-dong of the Monterey Institute of International Studies in California says Central Asian countries are also wary of being caught between these powerful countries.

"They want to, on one hand, benefit from their interactions with these bigger powers but at the same time, maintain autonomy," he says.

As China's main vehicle of influence in the region, all eyes are now on how Beijing would lead the SCO to navigate the new security environment. Analysts ask whether the organization will continue to promote mutual security.

Member nations have been trying to expand membership to strengthen the organization. Mongolia has already gained observer status, while memberships for India and U.S. allies like Japan, Pakistan and Afghanistan may be considered.

But some analysts say inclusion of other powerful nations would only stalemate the organization and weaken Chinese influence.