Turkish President Recep Tayyip Erdogan is looking for a new feud, initiating a diplomatic skirmish with President Biden that could portend additional tensions within NATO as U.S. and European allies confront the wayward leader.

A brief period of conciliation between Erdogan and other members of the trans-Atlantic alliance ended this week, as Turkish officials renewed their accusation that the United States orchestrated an abortive coup against Erdogan in 2016. That allegation, uncorked as Erdogan faces student protests pertaining to his management of a leading university, met with a swift rebuke from Secretary of State Antony Blinken’s team.