Trump's own former intel chief worried that Russia had compromising material on him, book says

• Dan Coats, former director of national intelligence, worried about Trump's relations with Putin.
• According to a new book, Trump's behavior at a summit with Putin sparked his concern.

A former Director of National Intelligence was so concerned about Donald Trump's behavior at a summit with Vladimir Putin that he believed Russia might have compromising information on him, a new book says.

The claim came in snippets from "The Divider" by New York Times chief White House correspondent Peter Baker and New Yorker staff writer and CNN global affairs analyst Susan Glasser.

They were published by CNN on Wednesday.

According to the authors, Trump's behavior as president raised alarm among top officials, including Dan Coats, then the DNI.

Officials wondered about the root of Trump's hostility to NATO as president per the book. The authors say Trump made more serious efforts to withdraw the US from the alliance than was previously known.

Splintering the NATO alliance has long been one of Russia's main strategic goals.

Coats, the book said, was also troubled by Trump's behavior at his 2018 summit in Helsinki with Putin, where he publicly backed the Russian president's assertion that Russia had not meddled in the 2016 election. In doing so, Trump contradicted his own intelligence agencies.

"I never could come to a conclusion. It raised the question in everybody's mind: What does Putin have on him that causes him to do something that undermines his credibility?" Coats told an associate, the book says.

Trump's actions at the summit provoked a firestorm of domestic criticism, and Coats was incredulous when on a panel at a security conference he was told that Trump used the summit to invite Putin to Washington, DC.

The question of whether Russia may have damaging information on Trump is one of the longest-running controversies about the former president.

A dossier, parts of which are now discredited, compiled before Trump's 2016 election former British spy Christopher Steele said that Russia had damaging information on Trump it would use as leverage.

Special Counsel Robert Mueller did not find sufficient evidence to substantiate claims the Trump campaign had colluded with Russia in 2016.

Trump has long dismissed rumors that he is beholden to Russia, and has recently pushed the allegation that a cabal of officials concocted the scandal to damage him.

Still, Trump's praise for Putin and refusal to criticize the Russian leader has continued to raise concerns amid Russia's brutality in the war in Ukraine.