During the first Democratic presidential debate, the following exchange took place between Hillary Clinton and Bernie Sanders about US policy in Syria: [my emphasis]
CLINTON: ... And, to -- provide safe zones so that people are not going to have to be flooding out of Syria at the rate they are. And, I think it's important too that the United States make it very clear to Putin that it's not acceptable for him to be in Syria creating more chaos, bombing people on behalf of Assad, and we can't do that if we don't take more of a leadership position, which is what I'm advocating.
SANDERS: Well, let's understand that when we talk about Syria, you're talking about a quagmire in a quagmire. You're talking about groups of people trying to overthrow Assad, other groups of people fighting ISIS. You're talking about people who are fighting ISIS using their guns to overthrow Assad, and vice versa. I'm the former chairman of the Senate Veterans Committee, and in that capacity I learned a very powerful lesson about the cost of war, and I will do everything that I can to make sure that the United States does not get involved in another quagmire like we did in Iraq, the worst foreign policy blunder in the history of this country. We should be putting together a coalition of Arab countries who should be leading the effort. We should be supportive, but I do not support American ground troops in Syria.
CLINTON: ...Well, nobody does. Nobody does, Senator Sanders.
Clinton's claim that "nobody" supports sending US ground troops to Syria was fundamentally misleading, because whoever calls for the US to establish a "safe zone" in Syria - as Clinton did in her previous utterance to which Sanders was responding - is calling for "ground troops."
This fact was made clear by a well-publicized exchange in a Senate Armed Services Committee hearing on September 16 between Sen. John McCain, chair of the committee, and General Lloyd Austin, head of US Central Command ["CENTCOM"], in which McCain pressed General Austin to say that he favored establishing "safe zones" in Syria and General Austin refused to do so, on the grounds that a "safe zone" would require a "ground force." The video of the exchange is here. The full video of the hearing is here.
McCain: Would you recommend a no-fly zone in Syria?
Austin: I would not recommend it at this point, sir.
McCain: ... Would you recommend telling -- setting up a buffer zone in Syria where these refugees might...
Austin: It will take a ground force to be able to protect the refugees if we do that, sir.
McCain: Would you support a buffer zone which would then protect some of these refugees ...?
Austin: I don't see the force available to be able to protect them currently, sir. So I would not recommend it at this point in time.
Whoever calls for the US to establish a "safe zone" in Syria is basically saying, "I agree with John McCain that we should send US ground troops to Syria." Or else they are saying, "I believe in calling for a policy to be implemented without supporting the means to implement it." Or else they are saying, "I believe in calling for a policy to be implemented without understanding or caring what means would be necessary to implement it." Or else they are saying: "I believe that General Austin was lying when he said that ground troops would be necessary to establish a 'safe zone.'" What are the other possibilities?
(Have you noticed how Republicans who demand that we "listen to our generals" when they ask for more troops don't seem to be interested in listening to our generals when they say "that's not going to work unless we send troops"?)
The next person you meet on the street could be forgiven for not knowing that "safe zone" = "ground troops." Not everyone watches Congressional hearings, or follows them in careful media. But anyone who is running to be President of the United States, who is criticizing the Obama administration for not being "tough" enough in Syria, who claims to have a magic bullet called "safe zone" to make everything wonderful in Syria must concede that "safe zone" means "ground troops," so if they are calling for "safe zones," they are calling for "ground troops."
You can urge Congress to oppose the use of US ground troops in Syria here.