GEOFF BENNETT: On Christmas Day 1991, the Soviet Union ceased to exist and with it the Cold War.

At the same time, China was amid its rapid expansion and opening to the world.

Now times have changed.

Russia is again a principal American adversary now joined by a much stronger competitor, China.

The challenge presented by both nations and the missteps made by U.S. presidents in dealing with both along the way is the subject of a new book.

Here's Nick Schifrin.

NICK SCHIFRIN: After the end of the Cold War, successive presidents and administrations considered China an economic partner who should be integrated into the West.

And they tried repeatedly for resets with Russia.

Today, there's bipartisan consensus that China is the U.S.' most important long-term challenge.

And Russia is trying to redraw the borders of Europe, while hacking into U.S. government agencies and promising no-limits cooperation with Beijing.

That transformation of what the U.S. calls great power competition is the story told in the book "New Cold Wars: China's Rise, Russia's Invasion, and America's Struggle to Defend the West" The New York Times' David Sanger.

David, thanks so much.

Pleasure to have you back on the "NewsHour."

DAVID SANGER, Author, "New Cold Wars: China's Rise, Russia's Invasion, and America's Struggle to Defend the West": Great to be with you, Nick.

NICK SCHIFRIN: How, as you write, did bipartisan faith in globalization become -- quote -- what you call "the fantasy era" of 21st century foreign policy?

DAVID SANGER: After the fall of the Berlin Wall, there was just an assumption, a flawed assumption, clearly, that Russia and China, each for their own very different reasons, would pursue their economic interests.

And the theory was that this was such an overwhelming imperative for both countries that it would override China's interest in Taiwan.

Russia would set aside, they'd make a lot of noise about Ukraine, but they wouldn't really do anything.

And every element of that assumption turned out to be wrong.

And when you think about sort of the great either intelligence failures or the great wishful thinking of the past 30 years, that was at the core.

NICK SCHIFRIN: You point out that the U.S. and European leaders -- quote -- "projected U.S. and European thinking on authoritarian regimes."

How so?

DAVID SANGER: Well, we assumed that what they wanted was more interchange with the West, so that they would get more trade with the West.

And, of course, that runs directly contrary to authoritarian thinking.

So there was Bill Clinton, when he would go to Beijing university and tell the students, the Internet will set you free, right, that it will undercut the Communist Party.

He got it completely wrong.

And, by the way, I bought into that argument when he was making it.

Similar problem with Russia.

President Bush is floating down the Neva River outside St. Petersburg on a sort of party boat with Putin, Putin's then-wife with Laura Bush.

And they're all talking about how Russia will join the European Union, how one day it might join NATO, the alliance created to contain the old Soviet Union.

NICK SCHIFRIN: The mistakes that you point out, not only just decades ago, strategic key misperceptions that the U.S. had, but also after a key moment, 2014, of course, when Russia invaded and annexed Ukrainian Crimea.

And you write about -- quote -- "The West's failure to grapple with the new reality."

It was almost as if the U.S. and its NATO allies were collectively flying on autopilot, assuming that small course corrections would safely land the plane.

Explain that.

DAVID SANGER: That was, I think, in many ways the most egregious example of the wishful thinking I referred to.

So Putin went to the Munich Security Conference in 2007 and said: There are parts of mother Russia that need to come back into the fold.

And we pretty much ignored him and said, yes, he's making a lot of noise for people at home.

Seven years later, he took Crimea and, of course, the Donbass.

President Obama did not want to challenge him.

He said, I'm not going to go to war for a Russian-speaking former part of Russia.

And, meanwhile, the U.S. didn't even name the Russians as the aggressor in cyberattacks on the White House, the Joint Chiefs of Staff, the State Department.

And so the message that Putin got was, the U.S. will tolerate this stuff.

And a year after he took Crimea, the German chancellor, Angela Merkel, signed the Nord Stream 2 pipeline agreement with him.

Well, that's where things were until the weekend before they invaded all of Ukraine in 2022.

NICK SCHIFRIN: Which brings us to today's policies on Russia, and let's start there in Ukraine.

What is the Pit in Germany and what is Project Maven and how did the U.S. share a version with Ukraine?

DAVID SANGER: The Pit is a place.

It's an intelligence-sharing operation between the U.S., the British, and the Ukrainians, although they go through this sort of odd dance because President Biden, in his effort to keep the U.S. from being a direct participant in the war, has mandated that the United States could not give exact targeting data to the Ukrainians.

So, in the Pit, they sort of say, well, kind of look generally over here, or we think there's interesting activity here.

Project Maven is a project for integrating all of this data.

It's a way of seeing what the Pentagon calls a single plate of glass, all of what the military activity is of the enemy and also of your own forces.

And what's fascinating about it is, it's the war against Russia in Ukraine that has been the U.S. effort to battle-test this and other technologies.

NICK SCHIFRIN: And when it comes to the Biden administration's policies on China, you point out many of the measures that were dismissed by Trump's critics at the time as hawkish or ad hoc or fearmongering would end up repackaged and carried into the Biden years.

How much continuity has there been?

DAVID SANGER: None of the Trump era tariffs on China have been lifted.

I think you have got to give credit to President Biden's team for putting this into a bigger strategy of shifting forces to the Indo-Pacific, of building up the American semiconductor industry, although there were elements of that starting in the Trump era, so that we are not so dependent on those chips from Taiwan being produced 100 miles off the Chinese coast.

But, certainly, there were elements, including banning Huawei, the Chinese telecoms company, that you saw in the Trump administration.

NICK SCHIFRIN: And finally, David, the book title, "New Cold Wars," as you point out, China is much more integrated in and integral to the world economy than the Soviet Union ever was.

Why do you see these as new cold wars?

DAVID SANGER: The S in the title is important, Nick, because one of the differences from the old Cold War to what we're in now is that we have the dynamic of Russia and China operating together, as you suggested at the opening.

That never happened in the old Cold War.

That was exactly what Nixon and Kissinger were trying to prevent with the opening to China.

Now, of course, there is a partnership without limits, or that's what Xi Jinping and President Putin called it.

If, in fact, China and Russia can find something that is closer to an alliance, then we're going to be back in the hardened lines of the old Cold War, rather than this view of a globalized, borderless world that we had a bit of a pipe dream 30 years ago.

NICK SCHIFRIN: The book is the "New Cold Wars: China's Rise, Russia's Invasion, and America's Struggle to Defend the West."

David Sanger of The New York Times, thank you very much, as always.

DAVID SANGER: Thank you, Nick.