For all the decisions Gates made, I will always hold him in high regard for his role in bringing about the end of “don’t ask don’t tell.” While the official certification that will mark its demise will not happen on his watch, the end of the ban on gay men and lesbians serving openly in the military — and serving their country — would not have happened had he not faithfully followed through on the express wishes of President Obama to get it done.

This was was by no means easy. The resistance was definitely stiff. But Gates — and Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, who retires in October — instituted a process (see “buy time”) that made December’s historic repeal vote in the Senate possible.

Gates has been at the Pentagon a little longer than I’ve been at The Post. We’ve never met. But if we ever do I’ll greet him with four simple words: Thank you, Mr. Secretary.