Joel Barkan has a CFR contingency planning memorandum on the Kenyan elections in which he notes that:
The United States and others may have limited leverage over Kenya’s domestic politics, but they are not without options that would significantly improve the prospects for acceptable elections and help avert a major crisis. However, with little more than two months before the elections, Washington must intensify its engagement or forsake its opportunity to make a difference.
But the window might be closing fast on the international community to help Kenya avoid a repeat of 2007-08, when 1300 died and 300,000 were displaced after a bungled election. According to a report by the Global Commission on Elections, Democracy and Security (yours truly was a research assistant for the commission), evidence suggests that international interventions to encourage reasonably free and fair and peaceful elections are most effective when done well in advance to the polling day. In the Kenyan case, the structural causes of previous rounds of electoral violence were never addressed, and may yet lead to the loss of life this election cycle.
What can now be done to avoid large scale organized violence is to credibly convince the politicians and those who finance youth militia (chinkororo, taliban, mungiki, jeshi la mzee, baghdad boys, etc) that they will be held accountable. So far, as is evident in Tana River and the informal settlements within Nairobi, the lords of violence appear to be operating like it is business as usual.