A crisis in Sudan where 29 Chinese workers are being held captive has renewed pressure on Beijing to provide security for more than 800,000 citizens employed overseas.

Expectations that China could intervene in a distant crisis were raised last year when the People's Liberation Army won domestic acclaim for its role in the rescue of almost 36,000 workers from Libya in the midst of that country's civil war.

After more than two decades of double-digit increases in defense spending, this was widely seen as evidence of the PLA's growing capacity to conduct complex, maritime operations far from home.

Beijing's move in December to deploy armed border police on joint patrols of the Mekong River following the murder of 13 Chinese nationals in an attack on cargo shipping was also seen as part of this trend.

However, the Chinese military would be unwilling to attempt the kind of daring rescue that US Navy Seals mounted last month in freeing an American aid worker and a Danish colleague from Somali gunmen, according to experts on the Chinese military.

"China does not have the intelligence network, it does not have the political will and it does not have the military capability to conduct operations of that kind of audacity," says Gary Li, a London-based intelligence and military analyst with Exclusive Analysis, a business intelligence agency.

Beijing's growing military reach has also been on display since PLA navy warships in 2008 began escorting Chinese and foreign cargo ships in and around the Gulf of Aden as part of an ongoing international anti-piracy campaign.

This mission has also seen Chinese naval vessels come to the assistance of about 50 cargo ships that have been captured or freed from pirates.

And, on occasions, senior Chinese military officers have called for stronger measures in dealing with Somali pirates despite the fact that Beijing has been careful to ensure that its warships avoid armed clashes.

The chief of the PLA's general staff, General Chen Bingde, said on a visit to Washington last year that international forces should also target Somali pirates on land to hit at the organizers behind attacks on civilian shipping.

"It is all part of a creeping shift in China's willingness to deploy security forces overseas," says Christian Le Miere, a maritime security researcher at the International Institute for Strategic Studies in London.

"We will see more of this in the future."

China this week sent a team of civilian government officials to Sudan to negotiate the release of the hostages.

Rebels in the Sudanese border state of South Kordofan captured the construction workers last Saturday, the third abduction of Chinese nationals in the areas since 2004.

They are apparently being held as bargaining chips in a dispute between Sudan and rebels allied with the newly independent and oil rich South Sudan.

With so many workers and professionals employed offshore, analysts say Beijing will almost certainly need to plan for future emergencies.

"We will see more incidences of kidnapping or other dangerous situations for Chinese in the nearer future," says Sven Grimm, director of the Centre for Chinese Studies at South Africa's Stellenbosch University and an expert on China's investment in Africa.

"In very crude terms, more people simply increase the likeliness of something to happen to them. And, secondly, a number of countries in which Chinese businesses operate are unstable."

The Sudan kidnapping has led to calls in China for better protection for vulnerable citizens offshore. Threats to workers overseas trigger thousands of posts on blogs and social media sites urging the authorities to launch a rapid response.

Chinese media too calls on the government to do more to protect nationals overseas.

"No other powers have the same number of nationals living in underdeveloped and turbulent regions as China," the strongly nationalistic, state-controlled Global Times newspaper said in a September 31 commentary. "Ensuring their safety is a major challenge."

Even if China develops the military means to use force against pirates or kidnappers, most analysts believe it would require a fundamental shift in a long standing, cautious approach to the security elements of its foreign policy to clear the way for the use of force.

China has so far avoided establishing foreign military bases and alliances that would allow it to mount distant operations and shows no inclination to do so.

"It is highly unlikely that China would take the approach of using its special forces to conduct rescue missions on foreign territory," says Shen Dingli, a professor at Shanghai's Fudan University and an expert on Chinese security policy.

Shen adds that in all its deployments offshore, China has been careful to follow international law and consult with other nations.

Still, the presence of Chinese military was symbolically important, analysts say.

"It sent a strong signal that China is prepared to keep its citizens safe," says Gabe Collins, an Ann Arbor, Michigan-based specialist on maritime affairs for the China SignPost research group.