When a nuclear fuel enrichment site in Iran blew up this month, Tehran immediately said two things: The explosion was no accident, and the blame lay with Israel.

Such an independent action by Israel would be a major departure from a decade ago, when the country worked in tandem with the United States to set back Iran’s nuclear ambitions.

We look at what the blast says about relations between the United States, Iran and Israel.

Guest: David E. Sanger, a White House and national security correspondent for The New York Times.  

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Background reading: 

• After the blackout at the nuclear plant in Iran, Tehran threatened reprisals, while Washington denied any involvement in the apparent attack.
• Iran vowed to increase uranium enrichment in response to the explosion.
• Another round of talks in Vienna about reviving the 2015 nuclear accord has been positive, despite the feuding over the nuclear plant.

For more information on today’s episode, visit nytimes.com/thedaily. Transcripts of each episode will be made available by the next workday.