Tens of thousands of anti-American Iranian protesters marched today on the former U.S. embassy in Iran, part of what the Associated Press described as “Tehran’s largest anti-U.S. rally in years.” Reports noted pervasive chants of “death to America,” and called attention to a speech by Saeed Jalili, a senior adviser to Supreme Leader Ayatollah Ali Khamenei.

“Fighting the global arrogance and hostile policies of America is the symbol of our national solidarity,” said Saeed Jalili, who lost to Rouhani in June’s election and later was replaced as the country’s top nuclear negotiator. The choice of Jalili as the main speaker to the crowd showed how high the rifts reach in Iran.

The protests threaten to deepen skepticism regarding the degree to which Iranian president Hassan Rouhani is willing or able to substantially reform Iran’s foreign and domestic policies. They come on the same day as reports emerged that a commander of Iran’s Revolutionary Guards Corps (IRGC) was killed in Syria, where Iran has provided critical logistical and military support to the Bashar al-Assad regime. Last week the BBC aired a video documenting what the outlet described as “the extent of Iran’s involvement,” in Syria, including active participation by top IRGC figures. Rouhani himself has repeatedly and explicitly pledged to stand by the Assad regime, opposite U.S. calls for the strongman to step aside in order to facilitate a peaceful resolution to Syria’s almost three year old conflict.

[Photo: CBS Evening News / YouTube]