"These actions were highly provocative, unsafe, and unprofessional and call into question Iran's commitment to the security of a waterway vital to international commerce," Raines said in an email. "While most interactions between Iranian forces and the U.S. Navy are professional, safe, and routine, this event was not and runs contrary to efforts to ensure freedom of navigation and maritime safety in the global commons."
The rockets were likely glorified rocket-propelled grenades, Cordesman said, as many revolutionary guard ships carry light armament.
Iran's elite Revolutionary Guard provoke confrontations with Western forces and showcase their prowess in high-profile exercises, as in this 2010 drill where go-fasts attacked a target vessel.
Photo Credit: AFP/Getty Images
"There have been cases in the gulf, where normally there is relatively tight supervision and both sides cooperate — at least in ignoring each other properly — but there have been cases where the guards have deliberately acted out," he said.
And in some cases, he added, officers responsible have been promoted later, "sort of as an award for obeying orders, showing initiative or being symbol of the guard's independence from the rest of the structure in Iran."
That's not to say that those actions would be endorsed outside of the service.
"At the same time it seems unlikely that any given officer would do this, and almost impossible to believe that they didn't realize what the political effect would be," Cordesman said.
The climate is tense following the signing of a nuclear deal earlier this year, as the terms continue to be carried out. Iran recently transferred a large amount of enriched uranium to Russia, but Cordesman said that wasn't necessarily a reason for the guard to show force.
It is possible, however, that these stunts could continue — or even spark larger tensions.
"It is a very uncertain time, and it's further unlikely that the revolutionary guards are not going to find ways to assert hard-line positions and occasionally protest the U.S.," he said. "It's unclear that the Supreme Leader would choose to stop them, simply because even though he's allowed the terms of the nuclear agreement to move forward, his statements have often been very hard-line."
Iran will be as big of a problem in 2016 as the Islamic State group, Cordesman said, "and at least as serious a threat."
Meghann Myers is the Pentagon bureau chief at Military Times. She covers operations, policy, personnel, leadership and other issues affecting service members. Follow on Twitter @Meghann_MT