The swirl of world events is incredible. Throughout the Obama administration, VP Biden has been in the center of national security decision-making. He liaised with leaders in Iraq and Egypt at critical junctures. He delivered speeches in Moscow, Beirut and elsewhere. So where is he now?
No court politics here, a review of the Vice President's schedule shows he is in regular meetings with the President and key national security figures - Combatant Commanders, SecDef, and this morning he hosted a meeting with the Secretary of State. But Biden is not taking a public role in explaining administration policy. Hillary Clinton and Robert Gates are, why not?
The VP has NO formal powers (unless specifically delegated by the President.) In upper levels of government, according to the classic Bureaucratic Policies and Foreign Policies a key question is "who has the action?" That is which official in which agency can actually sign off on an initiative. The VP doesn't have it. SecDef and SecState have a formal role in war-fighting and diplomacy. Having the VP out front in place of the President is useful in many situations, but not when forces are actually deployed. It would be Constitutionally and politically problematic to have Biden take a leading role.