For decades, one golden rule has guided America's military involvement in Africa: Stay out. Generally speaking, the reason was a sense that the strategic stakes did not justify the risk. When we deviated from this rule, we often learned lessons the hard way that seemed to reinforce its validity, as in Somalia in 1993. And while presidents often profess a stronger interest in Africa than their actions would imply, they tend to say such things when not in the White House mdash; witness Bill Clinton calling the nonintervention in Rwanda's 1994 genocide his greatest regret as president, or Sen. Barack Obama calling for more assertiveness in the Democratic Republic of Congo, or DRC, and Sudan...