Mark Halperin

But really, this is where I think things are.

And in the last 36 hours, I have...

I've developed doubts about this mission, and that's based on talking to people, including people in the administration who have doubts and concerns about where we are.

Things are going well, and I'll take those off, and they shouldn't be ignored, but this is not – the level of concern is higher publicly and privately amongst many.

than it was just a couple days ago.

Back during the Vietnam War, Walter Cronkite had what's called the Walter Cronkite moment, where he came back from a reporting trip to the region and spoke out against the Vietnam War.

It had an extraordinary effect on the conduct of the war.

people said, basically, if you can't hold Walter Cronkite, then you've lost the country.

I'm not Walter Cronkite, and I'm not here to say people should abandon this effort.

But almost every journalist who's serious about holding the government accountable always has looked at that Cronkite thing to say, if there's a conflict in some way, you're a reporter and you're a patriot.

You support America's military.

But you also know that sometimes the military is used in ways by political leaders that isn't rational, that isn't sensible.

And so there's no conflict really between speaking out when you see that a war effort may not be going well or isn't going well.

And supporting the military, even supporting the objectives of the war, getting the communists out of Vietnam, a reasonable objective.

But if the war is not working, if the theory of the mission is not working, it's incumbent upon journalists to say so.

I'm going to tell you today why I'm concerned.

I'm not telling you the president's foolish to have done this in the beginning.

I'm not telling you the mission should be ended.

But I want you to hear what Walter Cronkite said back during the Vietnam War and listen to the tone he had, which was very nuanced and very specifically tailored to the moment.

This is Walter Cronkite, 1968, on a special report from CBS News.