No, not even close.
Robert McNamara was the Sec. of Def. who was instrumental in making the Generals conduct the 'Rules of Engagement', (ROE), that we were forced to use in Vietnam.
Your a soldier, you know what happens when the Military is constrained in their efforts to kill the enemy.
It was a huge morale buster and this one policy was the Number #1 reason we 'lost' that f*cking war.
I know, I was there.
I know full well what a failure McNamara and his policies were. I also know that while Mattis is not leading a war of that magnitude, he is just as bad in not fighting the war against lunatic left wing social experiments crippling the military. One lost a war on the battlefield, the other is losing the culture war. Mattis is a disaster.