Insiders say the arrests confirm that the Revolutionary Guards’ top echelon is now committed to curbing corruption and smuggling by its forces, which control all of Iran’s borders.

“It took a lot of effort, but President Rouhani has convinced the top commanders that if systematic corruption and favoritism are not taken seriously, the pillars of the regime will be undermined,” said Saeed Laylaz, an economist close to the government. “These cases are the tip of an iceberg of wide and systematic corruption in the country at all levels of the state.”

In most of the world, the Revolutionary Guards Corps is known for its military wing, which has been leading Iranian efforts to support its ally, President Bashar al-Assad of Syria, in his fight against rebels and Islamic State militants. It has sent thousands of Iranian soldiers to advise and to fight, helping to tip the balance in both wars. Domestically, the Revolutionary Guards oversee Iran’s aggressive missile program, which has caused enormous friction with the Trump administration.

In line with its increasingly prominent military role, the Revolutionary Guards’ budget for military and missile activities has increased recently. But its economic activities are increasingly seen by top officials as a liability.

It was the United States-led imposition of punitive international sanctions during the Obama years that empowered the Revolutionary Guards’ role in the economy. At the height of the sanctions, beginning in 2009, the Iranian government found itself cut off from international credit. With foreign companies pulling out and global banks unwilling to finance trade or investment, Tehran was forced to turn to the Revolutionary Guards to keep the country running.

“During the sanctions, we couldn’t export, we needed goods. The Guards stepped in, and we are proud of it,” said Hamidreza Taraghi, an analyst close to Iran’s leaders. He described how the Revolutionary Guards took over oil projects from companies like Royal Dutch Shell, sold oil to some willing countries and engineered complex methods of transferring cash into the country. “They brought in hard currency,” he said. “They saved the country.”