Lloyd Austin knows the military top to bottom, and that’s good. After graduating from West Point in 1975, the retired general served the Army and his nation for four decades, rising to lead the 10th Mountain Division in Afghanistan, then to command troops in Iraq, then to run U.S. Central Command.

Even as the prospect of his becoming the first Black defense secretary inspires a diverse nation and military, Austin’s successes and failures on these many tours of duty warrant serious scrutiny from the Senate, as do his consulting work and service on various corporate boards since retiring.

What need not reflexively trip up his nomination as Joe Biden’s choice to oversee the Defense Department is that he hung up the uniform in 2016, which means he’ll need a waiver from Congress to run the Pentagon.

Federal law requires a military officer wait an arbitrary seven years, down from 10, before taking over the Defense Department. The sound reason: Ever since George Washington went from politician to general to politician again, America has prided itself on ironclad civilian control of the armed forces. Here, in stark contrast to lesser nations, men with chests full of medals take orders from officials elected by the people, and the latter never reflexively defer to the former.

It is well and good to test Austin on his independence from what Dwight Eisenhower, president and general, in 1961 dubbed the military-industrial complex, but there’s no magic to the particular seven-year cooling-off period.

If most senators (including Maine’s Susan Collins and Angus King) thought retired Gen. Jim Mattis – who’d been in civilian clothes four years when Donald Trump tapped him – deserved a chance, they should also extend one to Austin.