By Carlo Muñoz - 03/06/13 06:16 PM EST
The four-star generals' confirmations leave Brennan as the Obama administration's final national security nominee awaiting Senate confirmation.
While Rodriguez' nomination sailed through the Senate Armed Services Committee with relative ease in February, Austin's bid was blocked by panel member Sen. Lindsey Graham (R-S.C.) over concerns on the looming U.S. drawdown in Afghanistan.
The Pentagon is planning to pull out half of the 66,000 American troops still in country by this spring. The final withdrawal of the remaining 34,000 troops in Afghanistan will begin after the country's presidential elections next April.
That said, Graham's concerns and subsequent hold on the Austin nomination were rooted in what the U.S. presence in Afghanistan will be after 2014.
Specifically, Graham wanted Austin to provide his take to the South Carolina Republican on the administration's pending plan for postwar Afghanistan.
On Tuesday, Mattis told the Senate defense panel he recommended a 13,600-man force to remain in country after the White House's withdrawal deadline.
That number, Mattis added, could be supplemented by a NATO-based postwar force of roughly 7,000 troops.
That U.S.-NATO force number is significantly higher than recent reports of a 8,000 to 10,000-man force recommended by now-retired Gen. John Allen, the former top commander in Afghanistan.
After Tuesday's hearing, Mattis said his postwar troop recommendation was open to revision, and that a smaller troop number may be all American and allied commanders need after 2014.
"That was my recommendation at one point in time, now [with] all the dynamics of the battlefield . . . we have a lot of reason to believe the Afghan National Security Forces are improving all the time," Mattis said. "Their boys are fighting well."
That said, Graham told The Hill his postwar concerns on Afghanistan were not necessarily tied to the numbers themselves, but the administration's insistence on setting "arbitrary" force levels before the war has come to an end.
"I can live with 13,600 [troops]," Graham said. "What I cannot live with is an arbitrary number" that will tip off enemy forces as to what a U.S. force presence may look like in Afghanistan.
For his part, Senate Armed Services Committee chairman Carl Levin (D-Mich.) said Tuesday he was not opposed to the 13,600 number, but admitted he personally would like to see a postwar U.S. force fall more along the lines of the administration's suggestions.
That conflict between the political calculations of the White House and the military recommendations of combat commanders could end up forcing the U.S. "to drop the ball" in Afghanistan next year, Graham said Tuesday.
During Austin's confirmation hearing in February, Graham pointed out the conflict between the then three-star general and the White House over postwar troop levels during the U.S. drawdown in Iraq.
Austin, who was the top American officer at the time of the Iraq withdrawal, suggested the Pentagon leave behind a 16,000-man force in Iraq after the U.S. withdrawal from the country in December 2011.
The Obama administration, on the other hand, suggested a maximum of 10,000 U.S. boots on the ground in Iraq is all that would be needed to maintain security in the country and back up Iraqi security forces in the country.
In the end, the White House opted not to leave any troops in the country, due to a lack of a troop immunity deal with Baghdad.
But Graham said he did not want the same political calculations that created the disconnect between the administration and the Pentagon in Iraq to be repeated in Afghanistan.