China began holding a massive military exercise this week, deploying 50,000 troops to areas far from their bases for live-fire drills.  Military analysts say the exercises are not only meant to show the world how China's military is developing, but also to show it is ready to respond to unrest, be it in Xinjiang, Tibet or other parts of the country.

The two-month long exercise, called "Stride 2009" began earlier this week and will last through the 60th anniversary of the creation of the People's Republic of China on October 1. State media have trumpeted the exercise, calling it the largest ever and unprecedented.

Reports say the exercise will involve troops from China's major military regions of Shenyang, Lanzhou, Jinan and Guangzhou.

China's force of 2.3 million troops is the world's largest standing military.

June Dreyer, a China military analyst and professor at the University of Miami in the U.S. state of Florida says the exercise is both an international and domestic show of force.

"I think this is a demonstration affect, not only to the rest of the world, 'look we are coming along here do not mess with us', but also really internally because of the problems they have had in Tibet and Xinjiang, and also with Han Chinese who are very unhappy with the way things have been going," she said.

As the 60th anniversary nears, and in the wake of last month's riots in Xinjiang, Chinese authorities appear to be clamping down harder than ever on any form of criticism.

In recent weeks, China has put on trial activists who have fought for the rights of victims of the Sichuan earthquake, revoked the licenses of more than 50 lawyers and banned two groups that fight for human rights and against discrimination.

Authorities have also recently made it difficult for reporters, including those from Voice of America, to get visas to work in China.

As it tightens control, China says its anti-terror security forces are stepping up efforts to ensure a safe National Day this year.

Late last month, China gave foreign journalists a rare glimpse of the army at a base on the outskirts of Beijing.

At the gathering, Leng Jiesong, a senior colonel at China's Ministry of Defense, told reporters that to beef up security for October 1, the military was building on experience gained from its Olympic security work last year.

Leng says the military is taking measures similar to those used during the Olympics last year. Leng says the military is doing its best to maintain the safety of the capital during its October celebrations.

Military officials say security will be even more challenging for National Day celebrations because unlike the Olympics the celebrations will take place at numerous locations.

China's soaring annual defense budget has prompted worried calls from the United States and other countries for Beijing to explain more clearly how and why it is spending defense funds.

Earlier this year, Beijing said it would increase its defense budget this year by almost 18 percent to $58 billion. China notes at that amount its defense spending is still far beneath that of the United States.

Andrew Yang, a Chinese military expert in Taiwan, says China is holding the two-month exercise to show the world and its own people that the military meets Beijing's needs.

"They have to show that they are actually living up to the expectations of the country. And also at the same time, send a message abroad into the international community, that do not mess with the Chinese, they possess the capability to defend their own territorial integrity and sovereignty if they want to do so," he said.

Yang adds that the long-range exercises will not only highlight the military's ability to ensure security within China's borders, but beyond them as well.

Professor Dreyer says that while the military is rightfully proud of the progress it has made and wants to show that off, she does not see why China feels a need for such displays of force.

Especially, she adds, given the ease with which security forces have handled unrest in the past.

"I do not strictly understand why because it seems to me that they were able to handle the problems in Tibet and Xinjiang very quickly," she said.

Dreyer says that while China is clearly capable of squelching unrest, the government has yet to address the underlying problems that trigger instability.  They include poverty, income inequality, pollution and corruption. And until it does, she says, unrest will continue to flare up.