Over the weekend, President-elect Biden reached out to former CENTCOM commander GEN Lloyd Austin (ret.) and offered the job of Secretary of Defense, a source familiar with the offer tells me; Austin accepted.

2/ For several weeks, there have been discussions about several top candidates serving as SecDef, including Austin, Jeh Johnson, Michelle Flournoy, and Sen. Tammy Duckworth. Austin emerged as the leading candidate last week.

3/ Biden as VP worked with Austin in a variety of positions, most prominently when Austin was commander of CENTCOM from 2013-2016, when they had discussions on a range of issues including the Middle East and Central and South Asia.

4/ Before that, but also during the Obama-Biden administration, Austin was vice chief of staff of the Army and commanding general of US forces in Iraq.

"They've known each other for a long time," the source told me. "There's a comfort level."

5/ The source said that "the historic nature of the pick" -- Austin if confirmed would be the first black Secretary of Defense -- "is something Biden is excited about. Especially given the history of the US military being barrier breakers in a lot of areas."

6/ Given that Austin retired from the military in 2016 -- within the seven-year window for a Secretary of Defense nominee who was a military officer -- the Senate would need to approve a waiver for him to serve in the Secretary role, as there was with Mattis.

7/ "There has been engagement with people on the Hill about a waiver," the source says, adding that the team is "hopeful leaders of the committees and members responsible for bringing that forward will support that," particularly given the historic nature of the nomination.

8/ Austin also, the source says, "knows the Pentagon inside and out" and would be "an excellent person to run logistics on COVID-19 vaccine distribution."

He also "knows the cost of war firsthand," the source says, "having informed families who have lost loved ones."