More from the "That buck seems not to be stopping anywhere at all" department: Disparate inquiries into abuses of prisoners in Iraq and Afghanistan have so far left crucial questions of policy and operations unexamined, according to lawmakers from both parties and outside military experts, who say that the accountability of senior officers and Pentagon officials may remain unanswered as a result. No investigation completely independent of the Pentagon exists to determine what led to the abuses at Abu Ghraib prison, and so far there has been no groundswell in Congress or elsewhere to create one. But on Capitol Hill, even some Republicans have begun to question whether the Pentagon's inquiries are too narrowly structured to establish the causes of the abuses, as Defense Secretary Donald H. Rumsfeld and others have pledged to do, and then to determine if anyone in the chain of command was responsible for them. Some House Republicans, bucking their leaders who have said the focus on Abu Ghraib is distracting from the larger effort in Iraq, have joined Democrats in urging a more aggressive review of the investigations. In the Senate, members of both parties said there remained major aspects that fell outside the scope of any of the investigations that are under way — including the role of military lawyers in drafting policy on detainees and the involvement of civilian contractors in their interrogations.