By Mark Landler

New York Times News Service

Iran protests — Anti-government protests roiled Iran on Tuesday, as the death toll rose to 21 and the nation’s supreme leader blamed foreign enemies for the unrest. But the protests that have spread to dozens of Iranian cities in the past six days were set off by miscalculations in a long-simmering power struggle between hard-liners and reformers. By Tuesday, Iran’s leaders could no longer ignore the demonstrations and felt compelled to respond publicly. Ayatollah Ali Khamenei, the supreme leader, blamed outside “enemies” but did not specify whom. President Hassan Rouhani, a moderate, appealed for calm while saying the protesters had a right to be heard. But the anger behind the protests was directed against the entire political establishment.

— The New York Times

WASHINGTON — President Donald Trump has given full-throated support to the anti-government protesters in Iran. But the rising tide of unrest there complicates an already vexing decision for him: whether he should rip up the nuclear deal struck by his predecessor, Barack Obama.

Starting in two weeks, Trump faces a series of deadlines on whether the United States should reimpose sanctions on Iran that were lifted as a result of the agreement. Trump has already disavowed the deal, and he warned Congress and European allies last October that if they did not improve its terms, “the agreement will be terminated.”

With little progress on that front, and signs of a crackdown in Iran, analysts worry that Trump’s patience will run out. But they fear that if he acts now, it would shift the blame from the Iranian government, which is besieged by the protests and charges of corruption, to the U.S., which would be seen as forsaking an agreement with which Iran is complying.

The White House deflected questions Tuesday about how the protests would affect Trump’s calculus. “He’s going to keep all of his options on the table,” the press secretary, Sarah Huckabee Sanders, said. Trump’s ultimate goal, she added, was for the Iranian people to have “basic human rights” and for Iran to stop backing terrorism.

For Trump, the first major eruption of political unrest in Iran since 2009 carries opportunities as well as risks. Sanders emphasized the White House’s unyielding support for the demonstrators, which she contrasted to the more reticent approach taken by Obama in 2009 during protests that became known as the Green Movement.

The State Department on Tuesday urged Iran not to restrict access to social media services like Instagram and messaging platforms like Telegram, which the protesters are using to spread word about anti-government gatherings. It encouraged Iranians to use virtual private networks to sidestep the government’s efforts to block them.

Trump himself sought to link the grievances of the Iranian demonstrators to his predecessor’s policies, saying that the corruption of Iran’s leadership has been fueled by the benefits of the nuclear deal negotiated by the Obama administration.

“The people of Iran are finally acting against the brutal and corrupt Iranian regime,” he said in an early morning tweet. “All of the money that President Obama so foolishly gave them went into terrorism and into their ‘pockets,’” he added, apparently referring to the Iranian funds that were freed up when Iran agreed to constraints on its nuclear program.