Two retired generals spoke at the national political conventions last month — one in favor of the Democratic candidate and one for the Republican.
At the Democrats' convention, Marine Corps Gen. John Allen offered a thinly-veiled swipe at Donald Trump.
"But I also know that with [Hillary Clinton] as our commander in chief, our international relations will not be reduced to a business transaction," Allen said.
At the Republican convention, Army Lt. Gen. Michael Flynn joined in the crowd's chants to arrest Hillary Clinton.
"Lock her up, that's right," Flynn said. "Yeah, that's right, lock her up."
These high-profile appearances have spurred a third retired general to step forward. Army Gen. Martin Dempsey, former chairman of the Joint Chiefs of Staff, is asking his fellow retired generals to be quiet.
"The American people should not wonder where their military leaders draw the line between military advice and political preference," Dempsey wrote in a letter to the Washington Post. "And our nation's soldiers, sailors, airmen and Marines should not wonder about the political leanings and motivations of their leaders."
The role of the military is set out in the Constitution and is based on trust, Dempsey told NPR's Renee Montagne. Delving into politics undermines that trust, he said.
"I was upset," he said, about generals at the conventions, "not at the two individuals, necessarily, but that somehow, the message that we have been sending about the proper role of senior leaders, both on active duty and beyond, had not made it every place it needed to make it."
To hear their full conversation, click the audio link above.
On the military's role in government
We very clearly are responsive to and supportive of our elected officials ... in order to sustain that relationship both with elected officials and the American people, really the foundation of all that is trust. The issue for me was that if we begin to become part of partisan politics, inevitably that trust will break down with some segment of society ... I wouldn't begrudge them a bit if they were speaking privately to candidates and giving them their advice. But it wasn't appropriate, in my judgment, that they spoke at a political convention.
On retired military officers' right to free speech
The freedom of speech argument is the one that is often invoked. But here's the reality: Generals and admirals are generals and admirals for life.
They can do this. There's no law that precludes them from doing this. ... The military profession is held in great esteem by the American people. The image of the American professional officer is one who is on guard for the nation, who is representative of all the people, who is subordinate to elected officials, not the image of someone giving an angry speech at a political convention.
On generals who have become politicians and presidents themselves
I think we do well to have military experience in the Congress of the United States. But here's the difference: If you run for office, what you essentially do is you put yourself into a position where you will now be accountable to voters. If you're speaking as a general or an admiral as part of a political campaign, you're not accountable to anyone.
And by the way, you're making life much more difficult for those who continue to serve, who actually are accountable for the actions of the United States military as they deploy them across the land in response to elected officials.
On the difficulty of mixing politics and the military
I've served at high levels for the last three presidents, and one of the things that is very clear to me is that to be a very effective military adviser, you have to have the trust of those you're advising. My assertion here is that when general officers and admirals become politicized, it can reflect back on those currently serving. It's my instinct that there will be certain elected officials who begin to be concerned that the general officer corps and the admirals are becoming politicized, and if they become concerned about that, that trust relationship begins to break down. The expectation is that you are neutral to politics so that you can do your job, no matter who's elected.