The slaying of six Red Cross workers in Congo only days after a missionary and her infant child were killed in Peru is a stark reminder of the dangers faced by those who undertake missions of mercy to isolated parts of the globe.

The jungles and remote highlands where they venture may be mapped now. They may be connected to home bases by cell phones and laptop computers. But in some ways, the dangers are more chilling than decades ago, when the primary threats were disease, marauding animals or spear-carrying warriors. While natural dangers remain, humanitarian workers are increasingly exposed to political instability or violence related to drug cartels.

Considering the peaceful purposes of these missions, the deaths seem all the more horrible and unfathomable. The six workers of the International Committee of the Red Cross shot and hacked to death in a Congolese area torn by civil war were attempting to carry medical supplies to a remote hospital and help reunite family members separated by the fighting. Their deaths come only four years after the slaughter of six Red Cross nurses in Chechnya and the slayings of three others in Burundi.

The military shooting that took the lives of missionary Roni Bowers and her seven-month-old daughter last week in Peru may be less overt — her plane apparently was mistaken for a drug flight — but it, too, underscores the risks of modern missionary work. The remote area where American missionaries have worked for decades is now a popular transit zone for planes carrying unrefined cocaine to Columbia.

As today’s front-page story about Tim and Wendy Freeze makes clear, modern missionaries don’t dwell on the dangers. They might not even consider themselves courageous.

But that’s one part of humanitarian work that hasn’t changed. It takes courage and selflessness to dedicate one’s life to helping others, especially when it means facing new risks along with some of the old ones.