Also, because Iranian nuclear sites like the Fordow enrichment facility are buried underground and therefore hard to hit, Trump would most likely target nonnuclear infrastructure like oil refineries, according to Graham.

“If they try to rapidly expand their nuclear program, they might lose their oil program,” he said. “The best way to stop their nuclear program is to crush the Iranian economy.”

Iran’s promise to ramp up its enrichment is surely meant to give Tehran leverage and also to pressure European countries who want to preserve the nuclear deal into pressuring Washington. The Trump administration, having withdrawn from the nuclear deal, is hard-pressed to call for its enforcement now.

By July, Iran had already breached a 300 kilogram limit for its stockpile of uranium enriched to 3.67 percent, a ceiling Tehran had promised to stay under until 2030, according to the nuclear deal. If that stockpile were enriched to higher levels, the timeline for Iran to produce a nuclear bomb would shorten dramatically.