Our system of government doesn’t (shouldn’t) reside on the shoulders of 1-2 men. From a military standpoint, the generals have a responsibility to tell their civilian leaders when a campaign is ill advised.
I certainly agree. However...I read about a meeting Rumsfeld had with his generals, right before the 2002 Iraq invasion.
One general (I believe it was an air force general) asked what the plan would be if a guerrilla war broke out. Rumsfeld angrily told the group that the next person who brought up a guerrilla war would be fired.
So I wonder if the generals had spoke the truth from the beginning, but the politicians just weren't listening.