Iran has survived decades of sanctions. Faced with more, it is likely to escalate rather than surrender, analysts said.

© Arash Khamooshi/Polaris for The New York Times

French, German and British diplomats are working on a format for future negotiations — even if Russia has shown little interest.

© Nina Liashonok/Reuters

French, German and British diplomats are working on a format for future negotiations — even if Russia has shown little interest.

© Nina Liashonok/Reuters