CAMBRIDGE, Dec. 8 -- Americans, including Biden, will still face allies' concerns about whether they can be trusted not to elect another Trump in 2024 or 2028.

Friends and allies have come to distrust the United States. Trust is closely related to truth, and President Donald Trump is notoriously loose with the truth. All presidents have lied, but never on such a scale that it debases the currency of trust. International polls show that America's soft power of attraction has declined sharply over Trump's presidency.

Can President-elect Joe Biden restore that trust? In the short run, yes. A change of style and policy will improve America's standing in most countries. Trump was an outlier among US presidents. The presidency was his first j...