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Here’s what you need to know:

Bannon’s mea culpa

• Days after Stephen Bannon was quoted in a new book accusing Donald Trump Jr. of treason, the former chief strategist backed away from the comment on Sunday, saying President Trump’s eldest son was “a patriot and a good man.” (Read Mr. Bannon’s statement here.)

Over the weekend, the president and his supporters harshly criticized the book, “Fire and Fury: Inside the Trump White House,” which raises questions about the president’s mental fitness. In a tweet, Mr. Trump called himself a “very stable genius.”

• Genius or not, the president has left many countries unsure whether his messages on Twitter reflect U.S. foreign policy or can be safely ignored. If his threats are hollow, what does that do to American credibility? Our chief diplomatic correspondent in Europe explored that question.