Dereliction, of course, is so harsh a term that it ought to be used with care and consideration.
Much of the war planning qualifies, most likely. The refusal to make tactical changes prior to the 2006 election probably qualifies. There are parts of Rumsfeld's mis-conceptualization of the "war on terror" that are in the running, but may not fit fully. Plausible assurances passed on to Congressman/Senators in bad faith before the AUMF, if any, probably fall under a separate header.
On deck today is the continual avoidance of the DoD to provide complete information on wartime costs. If ever there were clear indications that the Bush-Cheney-Rumsfeld Administration have played power politics with the war, this is it.
Cordesman has released a survey of war cost estimates:
Moreover, much of the CBO work presented in the briefing is taken from CBO studies that shows that the Department of Defense has failed dismally to control the future cost of military manpower, operations and maintenance, and procurement, research, and development. This work strongly indicate that the next President will face a legacy of a badly managed overall defense program ...
-A. Cordesman, CSIS, April 1, 2008 [a 55 page report]
This is just the softball stuff. Check out:
Projections are one thing. However, pressing for an unlimited engagement ("withdrawal upon 'success'") and failing to update the DoD's cost accounting systems is reprehensible double-speak. Passing out new rules to the field on what can be included in "supplementals" as far as equipment replacement, etc., also is indicative that the Administration is not serious about cost accounting for our prologued, violent, nation-building efforts.
[more on the estimates themselves, later]