1/ Weird how I keep forgetting that Twitter is not a good place for nuanced arguments. Or, really, any arguments.
But if anyone is interested in why I think it's a bad idea for Biden to pick as Sec Def a retired general who would need a congressional waiver to serve, here's why:

2/ (and, hint! It's not b/c of race!). FFS.

3/ Retired generals can make excellent sec defs.... in theory. But in practice, they usually do not. This is why Congress pass legislation mandating a 10 year "cooling off period" (later changed to 7 years) before retired generals could be Sec Def...

4/ Military officers are trained and habituated to doing things in particular ways, and the military has processes, assumptions and terminology that isn't always shared by civilians. (E.g., words like "planning" and "strategy" can mean quite different things.... ).

5/ One of the roles of the Secretary of Defense is to serve as the top translator between the military and the civilian policy-makers and political leaders:

6/ the SD has to understand what civ leaders want & interpret that in ways that translate into effective action on the part of the military, & understand military constraints & requirements, & be able to translate those into language and proposals that make sense to civ leaders.

7/ When people go more or less straight from senior military roles to senior civilian roles, it can be very hard for them to do that effectively.

8/ It's also important that the military be, & remain, non-partisan in nature. If senior military officers know they can move rapidly from retirement into positions as senior political appointees, there's a risk that instead of giving civilian leaders honest, non-partisan advice,

9/ they start shaping their advice to position themselves for future civilian political appointments.

10/ That's why Congress initially mandated a ten-year "cooling off" period before senior military leaders were eligible to serve as SecDef (though they shortened that to 7 years in 2008):

11/ they recognized that there should be plenty of time between senior military positions and having the very same people take up senior civilian political appointee roles. There have only been two waivers granted since 1948, one for George Marshall, the other for Jim Mattis--

12/ Neither turned out to be great SDs. And if Congress gets into the habit of granting waivers, it will defeat the purpose of having the cooling off period in the first place.

13/ Is nominating another 4 star as Sec Def the end of the world? No, and Lloyd Austin is a good and impressive man who will do his best to serve his country as SD just as he has done in uniform. Formalistic conceptions of civ control of the mil do less work than we assume....

14/ As I have argued many times myself. We often get fetishistic about norms of civ-mil relations and stop asking questions about what work they are actually doing.

15/ That said, noting that civ-mil norms don't do all the work we often think they do is not a reason to toss them aside without good reason.

16/ Right now, I think there are some even-more-powerful than usual reasons for Biden NOT to put a recently retired 4 star, no matter how wonderful, into the position of SecDef. DoD's civilian side has been decimated under Trump:

17/ tons of empty positions filled by people in acting capacities, for instance. And Mattis reportedly relied very heavily on his own network of former military subordinates and colleagues -- understandable, from his perspective, but the effect was

18/ to increasingly sideline civilian experts at all levels within the Defense Department during his tenure, and the Joint Staff and Mattis' personal staff were increasingly the locus of policy-decision-making.

19/ That balance urgently needs to be reset. The Pentagon is a vast but delicate machine: it can't run effectively without multiple kinds of expertise and experience, and when you lean to heavily on one skill set, the whole thing starts getting shakier.

20/ This is a moment when DoD needs someone who can come in, hit the ground running, play that vital role as translator & restore that some balance. Having a recently retired 4 star as SD risks upsetting the balance still further, and further demoralizing the civ side at DoD.

21/ I also just find this odd: the Biden team has repeatedly expressed a desire to deemphasize the military and highlight the importance of civilian capabilities. Picking a general so recently retired that he needs a congressional waiver sends the opposite message.

22/ I want to see more racial and gender diversity in national security and at DoD - but there are other exceptionally well qualified African Americans and women who were also on the shortlist, and who would NOT have required a congressional waiver to serve as Sec Def.

23/ Had Biden picked Jeh Johnson, for instance, ppl but would have celebrated him as the first Black SD pick. Had Biden picked Michele Flournoy, ppl would have celebrated her as the 1st female SD pick. Neither would need a congressional waiver to serve.

24/ I think Biden has been poorly advised. He should have chosen someone else as his initial pick; in less than three years Austin will be eligible to serve without a waiver and he could be Biden's 2nd SecDef.

25/ That's it. I'm disappointed that the Biden team went for a general. But we have other battles to fight and will move on. If Austin is given a waiver and confirmed, I and everyone else in the national security community will support him and celebrate his successes.