“‘Yesper’ is without competition the weakest SecDef in history,” tweeted Peter Singer, an author and strategist for the liberal-leaning New America Foundation, adding to POLITICO later: “From allowing loyalty purges of his own staff, to unprecedented interference in both the military justice and now promotion system, to delaying acting on CV-19, so as not to get ahead of the President's denial of risk … Esper has consistently kowtowed to the White House in not just a manner, but on matters never seen before in a SecDef.”
https://www.politico.com/news/magazine/2020/07/20/esper-defense-yes-man-reputation-370248