I think the reason can be found in the following article. - http://www.losangeleschronicle.com/articles/viewArticle.asp?articleID=9146 "Contrary to much ill-considered opinionating, the Maoists have not opted for peace in our time. Instead, their forces remain intact, even as they encourage the government to dismantle the only intact force that stands between the Communist Party of Nepal (Maoist), or CPN(M), and its ability to work its will, the security forces." NC has been strictly directed to keep all those ministries by USA via Richard Bouchar. IF UML gets teh Home (police) or Defense (Army) of the state, then Commies can rule NEpal easily, with Maoists rebel force controlling remore areas and RNA under UML can rule urban areas so that the whole Nation turns RED in teh world map. If that happens, it will be so shameful for USA, perhaps that's what USA thinks and hence asked NC to protect al those important strategic Ministries to themselves. Hope that explains.