President Barack Obama on Friday ordered U.S. troops to Central Africa to deal with a group called the Lord's Resistance Army. The approximately 100 troops aren't there to fight, the president stressed, which is a good thing because according to Global Security the LRA consists largely of child soldiers who have been abducted and forced to join. The LRA has been around for decades, but this is the first time U.S. forces have been sent specifically to face it.

What is the LRA? The rebel group led by Joseph Kony states in its manifesto that it wants to "overthrow [Ugandan] President Yoweri Museveni's government and replace it with one governed by the Biblical Ten Commandments," according to IRIN, the United Nations' humanitarian news service. The Ugandan government says it's not a rebellion, but "simply a terrorist group, with no political agenda," that has resisted efforts to mediate a peace. Child soldiers, some as young as 7, make up its rank and file, reportedly by Kony's design. "Kony is interested in children. If you tell a child who is terrorised and traumatised to commit an atrocity, the child will do it. This is not the same with adults," Carlos Rodriguez, a Catholic Priest from the city of Gulu who has been working for peace among the Acholi ethnic group, told IRIN. The BBC reports that "At least 30,000 people died as the LRA spread terror in northern Uganda for more than 20 years, displacing some two million people." It's not clear how many troops the LRA has, but an IRIN article from 2007 estimated its size at "as many as 3,000 LRA fighters, with about 1,500 women and children in tow."

Why is the U.S. getting involved? In short, it's because of a law enacted in May 2010, which authorized U.S. military action. According to Obama's letter to Congress on Friday, the U.S. has "supported regional military efforts to pursue the LRA and protect local communities" since 2008. But the limited support hasn't given those communities enough of an edge to defeat the LRA. "In the Lord's Resistance Army Disarmament and Northern Uganda Recovery Act of 2009, Public Law 111-172, enacted May 24, 2010, the Congress also expressed support for increased, comprehensive U.S. efforts to help mitigate and eliminate the threat posed by the LRA to civilians and regional stability."  Human rights groups such as the Center for American Progress's Enough Project have put pressure on Obama to take more aggressive action against the LRA. According to CNN, "Representatives of 34 groups in the LRA-affected areas of northern Congo, Central African Republic, and Southern Sudan wrote Obama in December, applauded his commitment to tackle the problem, and urged him to deal with the group." On Friday, Sen. Jim Inhofe, an Oklahoma Republican, praised the move to CNN: "I have witnessed firsthand the devastation caused by the LRA, and this will help end Kony's heinous acts that have created a human rights crisis in Africa."

What will U.S. troops supposed to do there? Essentially, they're to serve as advisers and guards. The special operations troops will go "combat-equipped," with the goal of "remov[ing] Joseph Kony from the battlefield," Obama wrote, but they're not being sent to engage the LRA themselves. "These forces will act as advisors to partner forces that have the goal of removing from the battlefield Joseph Kony and other senior leadership of the LRA. Our forces will provide information, advice, and assistance to select partner nation forces." The BBC has a bit more information:

Mr Obama did not provide any details about the deployment duration, but a US military spokesman later told the BBC that the "forces are prepared to stay as long as necessary to enable regional security forces to carry on independently".

The force will use hi-tech equipment to assist in what analysts say is a "kill or capture" policy, the BBC's Marcus George in Washington reports.

The deployment follows recent US legislation to help disarm the LRA and bring its leader to justice. The theory is, our correspondent adds, that without Joseph Kony, the movement will collapse from within.