New York (CNN Business) A version of this article first appeared in the "Reliable Sources" newsletter. You can sign up for free right here.

President Trump tweeted on Tuesday, "The world is at war with a hidden enemy. WE WILL WIN!"

Think of it as World War V, short for virus. Trump's aides are calling him a "wartime president." Governors and other public officials are increasingly using war analogies. "It's unbelievable how rapidly this crisis is growing right now," NYC mayor Bill de Blasio said on MSNBC Tuesday night.

Tuesday's most powerful warning came from CNN's own brain surgeon and chief medical correspondent Dr. Sanjay Gupta. For the better part of 20 minutes, Gupta and Jake Tapper said the American people are not doing enough to flatten the curve. Gupta said the country is "woefully underprepared" for what's coming.

After the remarkable Q&A, Dana Bash said on the air, "I have been working with Sanjay Gupta for a long time admiring him; listening to him for a long time -- I have never heard him like that, Jake." Tapper concurred: "He's the guy who says you're going to be fine." But not right now. "He is visibly frustrated," Bash said, "and as angry as Sanjay Gupta gets, at the fact that people aren't listening."

So I'm going to hand the first half of this newsletter off to him, in the hopes that his message can reach a few more people in positions of power...

"I'm worried"

Tapper and Gupta's conversation followed a live report from CNN's Dan Simon in SF, where large numbers of people were strolling along the Embarcadero despite the area's shelter-in-place order. Tapper said the business-as-usual behavior seen in the live shot was "enraging."

"I still really get the impression that people in many places aren't taking this seriously, and I think that's a problem," Gupta said. "I mean, we have seen what has happened in places around the world where this has not been taken seriously." He mentioned Italy.

Gupta said "there's been a great change in tone" from the federal government, including President Trump, who has been markedly more serious in the last two days. "What needs to happen in this country is, we need to break the cycle of transmission of this virus, and it doesn't look like that's happening right now. I'm worried these numbers -- they keep going up, and they're going to go up because of the testing, but I think they're going to go up as well because this virus continues to spread."

"Jake," Gupta continued, "you've known me a long time. I'm not someone who likes to be hyperbolic or shout these things from the roof. It's just not my nature. But we know what needs to be done. The government knows what needs to be done. Public health officials know what needs to be done. It's not happening right now. Again, I applaud the change in tone. I applaud the seriousness with which this is being taken at the White House and a lot of the comments that came from the W.H. But, you know, we're not seeing it translate into the action that is necessary right now."

Testing... hospital preparedness... social distancing... We know what needs to be done, yet "I don't think any of those things have been done yet, Jake," Gupta said. "We're still way behind on testing. It's not at all clear to me that hospitals are prepared for what's about to happen. And I think given... the different sorts of, you know, patchwork of recommendations around the country, people just aren't taking this seriously. They're going out and buying things, sometimes even hoarding things for their home, but they don't understand, I think, fundamentally, what is happening with this virus right now. Maybe because the numbers are so far behind, maybe because we're behind the curve. I don't know what it is. I've never seen anything quite like this. I don't think anybody has, but we are -- we're not doing what needs to be done right now."

Never before "have we been so dependent on each other"

Gupta and Tapper continued talking after a commercial break. "I'm not someone who likes to motivate through fear, inspire through fear, but there are lessons staring us right in the face when it comes to this," Gupta said . "And, you know, for a country that does so many things well -- and I think our public health system at times can do so many things well -- right now I think we're woefully underprepared."

I could see the concern, the pain, in Gupta's voice. I turned up the volume on TV as he said "next week, I don't know what we're going to be talking about, and I'm a little frightened to sort of think about that right now, Jake."

Gupta and Tapper said they're taking steps in their own lives, like cancelling childrens' playdates. "My youngest daughter had her birthday yesterday. We canceled her birthday party," Gupta said . "It was not an easy discussion to have with an 11-year-old. She understands, and it's the right thing to do. We need to set that example. There's all these things that are within our power and we're in this together. The good news part of this is that it is within our control, I think, to totally change the fate here or at least alter the fate of what's happening here. Maybe not totally change it -- but have an impact on where this thing goes. It's within all of us. How I behave, Jake, affects your health. How you behave affects my health. Never, I think, have we been so dependent on each other, at least not in my lifetime, and we should rise to that occasion."

Why the poor visuals from the White House?

Oliver Darcy emails: If you've tuned into the White House's daily coronavirus briefings, you've surely noticed: While the President and other officials are strongly encouraging the public to social distance, they themselves are not employing the practice themselves. It's not the most pressing issue, of course, but it still sends a perplexing message to those who are watching. Other state and local officials have led by example, distancing themselves during press briefings. So why hasn't the White House?

>> "CBS News W.H. correspondent Weijia Jiang "revealed Tuesday that an unnamed White House official referred to the deadly coronavirus as the 'Kung-Flu' directly to her face," Emma Tucker wrote...

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