I think he'd have to qualify it in terms of risk to the political objective, and as such it is really a menu of choices. This gets into negotiating the Ends/Ways/Means equation, or offering up options involving each and pointing to their associated risk(s).

This allows the political leader to make some judgments and assume their legal responsibilities and authorities as CINC.

That is not a cop out, it is the way we've designed our system. We (military folks) grow up learning to articulate the world in opportunities, advantages and risks. We may need to do a better job of articulating and communicating them to the political leadership, but that is what assessments and reviews are for, and it is incumbent upon that political leadership to ask tough questions and think.

Ultimately it is the political leadership that must summon or encourage the body politic to put forth the will, or must apply the argument for an increase in means, and ultimately its the political leadership that must stand for election/re-election. That said, the assessment or review put forward by the CDR is a good way to frame the costs of the political objective.

Best, Rob