Last week, President-elect Joe Biden announced that he would nominate Lloyd Austin, a four-star Army general who retired in 2016, for secretary of defense. However, to serve, Austin will first have to secure a bicameral congressional waiver, required by federal law since he has not been retired from active-duty military service for at least seven years.

In 2016, President Trump’s first defense secretary, Jim Mattis, required and received the same congressional waiver before his confirmation. Lawmakers in both parties expressed concern about granting another exception so soon after the last one. They are right to do so.