Beijing cracks down on Tibet....

But, the world is silent about China...

IN the ancient back alleys of Tibet's capital, Lhasa, a grim military operation has played out this week, hidden from the eyes of the world. As night falls, hundreds of Chinese troops fan out across this rebellious city, armed with riot shields and assault rifles.

They set up sentry posts on street corners and dispatch patrols in groups of six soldiers, three with shields and three with guns.

These patrols spend the night walking down the lanes of Lhasa's Tibetan quarter, looking for any signof dissent. They glare at me asthey pass, angry at the presence of a foreigner.

When the sun rises, the soldiers do not melt away, but are replaced by a new rotation of troops. The military stranglehold on Lhasa by day is maintained with one chilling addition -- snipers are installed on rooftops around the city's most holy site, the Jokhang Temple, ready to train their guns on the hundreds of Tibetan pilgrims praying in Barkhor Square below.

Only months after the Beijing Olympics, there is no post-Games euphoria in Tibet.

Hopes of greater autonomy and freedom have been stifled by Beijing, which -- stung by bloody anti-Chinese riots in March and by the indignity of the subsequent Olympic torch relay protests -- has come down on Tibetans with an iron fist.

During four days in Lhasa this week -- the first visit to Tibet by an Australian journalist since the March riots that left up to 200 people dead -- I witnessed a city creaking under the weight of the Chinese military.

In meeting local Chinese government officials, it was apparent that Beijing has lost patience with those Tibetans who oppose its rule and has chosen the path of zero tolerance.