Paris - This week brought relief in South Korea, as the Taliban released 21 Korean Christians held hostage for six weeks in Afghanistan.

The missionaries were part of a robust effort by Korean Evangelicals to work in "frontier missions" – places with few other believers. Yet after South Korea's reported deal with the Taliban to withdraw troops and possibly pay a ransom, the risks of private groups doing good in hot spots are being rethought by humanitarian and church groups.

One lesson is the interdependence of aid groups and the need to protect one other, especially in 2007 when outsiders are more at risk in many parts of Asia, the Middle East, and Africa. Missionaries and humanitarian groups must coordinate: conduct local assessments, know the unwritten codes, work with locals, and work together as a way to deflect harm that might ensue through rash decisions, they argue.

Unlike proselytizing in the West, "When [Evangelicals] go to Afghanistan, their actions have a huge impact on the rest of us and the and the things we're trying to accomplish," says Randolph Martin, director of global emergency for Mercy Corps International. "In [the South Koreans'] case, the Taliban also got a reward, because the Korean troops will pull out."

South Korea has also banned its citizens from traveling to Afghanistan since the 23 Evangelicals were captured in July.

In 2007, hot spots are ever more complicated, experts say.

The fall of the Berlin Wall, the 9/11 attacks, and especially the invasion of Iraq, have resulted in more fragmented and weaker states, the rise of guerrilla groups, land and power grabs, and manipulation of ethnic and religious feeling. The environment in places like Iraq, Darfur, Afghanistan, Somalia, Yemen, Haiti, and Gaza is a turbulent mix. On the ground is every type of foreigner – undercover intelligence, civil society groups, private security, and state military, doctors, construction teams, mine clearing groups, journalists, humanitarian aid workers, and church people, some of whom do both gospel and aid work.

Views on missionaries whose chief aim is sharing the gospel in hot spots vary widely among the nongovernmental (NGO) and religious communities. But even those who accept missionaries argue that good intentions, enthusiasm, and bravery must conjoin with a professional approach.

"To work in dangerous areas you need ... deep networks, and deep knowledge," says Jerome Larchu, a director of the Paris-based Médicins du Monde (Doctors of the World), which has volunteers in 55 countries. "You bring in skilled people, lots of locals – and only then do you send people in."

In February Médecins du Monde pulled its team out of Darfur for security reasons. But the doctors felt their mission wasn't over. This summer they put scouts into Sudan for eight weeks to travel, talk with locals, and assess risk – before going back in.

If missionaries or aid workers do not have the proper help and concept, "it is a problem for us," says Mr. Larchu. "I think anyone has a right to proselytize if they want to. But to locals, an NGO is an NGO; they don't know who we are. They don't make a lot of distinctions. They don't know who is legitimate. So NGOs are interdependent, whether we realize it or not. We have to gain local trust together."

Koreans followed 19th-century model
Broadly speaking, the Koreans in Afghanistan operated on a 19th-century missionary model that has evolved considerably in the US, says David Heim, editor of The Christian Century, a magazine in Chicago. "American churches going out to the world and converting people has been critiqued for a century, and most have learned from the criticism," notes Mr. Heim. "The South Korean churches seem to be in that older independent evangelical model of going off alone. Today relatively few mainline American churches do this. Most send small teams that partner with indigenous churches and local believers. It's more collaborative."

In the 1950s and '60s, mainline Protestants in the West began to help various independence movements in developing nations, and to work in social-justice causes abroad – but only where invited, and in an equal partnership with locals.

By the 1980s and 1990s, a rise in evangelicalism brought more fervor among Christians to go to new areas – including states in the former Soviet Union and Central Asia.

New way: work with locals
Serious mainline Christians who feel that sharing the gospel is part of the natural activity of their faith point to a long history of learning-by-doing among missionaries. The World Council of Churches has a "Commission on World Mission and Evangelism" that teaches this history and advocates that Christians learn the lessons of earlier missionaries.

Marian McClure, former director of worldwide ministries for the Presbyterian Church (USA) points out that, "The older organizations devoted to mission [do] work hard at not having to relearn lessons learned through mistakes made. The newer ones too often repeat those mistakes, but ... they also bring fresh energy and boldness and vision."

In the early 1990s, Presbyterians sent missionaries to Central Asia that had either lived there before or had mastered a local language. The approach built on conversations with indigenous believers, says Ms. McClure: "This proved to be a good security strategy as well. There have been many instances where US expatriates sent by mainline churches were kept safe by their hosts."

More workers, more killed
In the past decade, the number of NGOs has risen sharply, as have incidents of violence against them, say Larchu of Médecins du Monde and Martin of Mercy Corps. "More than 80 humanitarian workers were killed in 2006 – that's more than UN soldiers," says Larchu.

The number of religious groups is also rising and work closely with secular groups. "Worldvision, the Aga Khan Foundation, Catholic Relief Services – which makes no attempt to hide its name – they channel their faith into humanitarian efforts," says Martin. "When they come into a dangerous place, they either sit at the table with us, or work at cooperation. If, like the South Koreans, we don't know them, and they don't know us, that makes it more difficult for everyone."

Philip Leveque, director of CARE France, says the basics of humanitarian interventionism today are: sending an ethnically diverse team, employing locals, building over time, and becoming familiar with rules and procedures.

"The old days when 8 of 10 aid workers were white guys is over," Mr. Leveque says. "Maybe the main thing is to know when to leave." Every CARE mission now has a security chief who can overrule the head office and circumvent the local head of mission in most cases.

McClure says a public misconception abroad is that Christians want to "foist" their beliefs on others. "On the contrary, most Christians today suffer not from a tendency to foist our faith on anyone, but from a tendency to be excessively private about our faith," she argues. "I have never met a follower of a non-Christian religion who would respect someone who could not and would not express his or her beliefs."