In the latest incident of Iranian bullying at sea, four Iranian boats again closed in at high speed to a Navy destroyer in the Straits of Hormuz on Sunday. Once again the U.S. Navy destroyer, USS Mahan, fired warning shots after the Islamic Revolutionary Guard Corps boats did not respond to requests to slow down.
A U.S. Navy official said the warning shots fired on Sunday were just one of seven interactions the Mahan had with Iranian vessels over the weekend. Referring to other similar encounters, the official said there had been "a total of 35 in 2016 that were assessed to be unsafe and unprofessional".
The incident is the latest in a string of tense encounters between the two countries the last two years that has included Iranian rocket launches, drones flying over U.S. vessels and the capture of US sailors.
Since 1979, Iran established its naval doctrine of guerrilla and attrition, with emphasis placed on the ability to disrupt freedom of shipping through the Straits of Hormuz.
Accordingly, because of the embargo placed on Iran, its naval force prioritized asymmetrical capabilities meant to confront the technological advantages of the U.S. Navy in the Gulf — land-based, anti-ship missiles; underwater mines and small vessel swarms.
Preference was given to strengthening the naval branch of the Revolutionary Guards over building the regular navy, which remains small and outdated. In 2007, the realms of responsibility of the two navies were split — while the Revolutionary Guards' navy received overall responsibility for the Gulf arena, the function of the regular navy was reduced to activity beyond Gulf waters.
Because of the weakness of the regular Iranian navy, most of whose vessels date to the era of the Shah, and the United States' naval supremacy in the Persian Gulf, Iran preferred to purchase and construct many small, fast vessels (some unmanned) and miniature submarines and to repurpose civilian ships to military missions.
Some of the vessels of the Revolutionary Guard navy are armed with anti-ship missiles; some have been adapted to lay underwater mines and some are laden with explosives.
One of the motivating factors in adopting these methods lies in their plausible deniability. A foreign response to damage using these means may be less painful than it otherwise would be if it is difficult to pin the blame on Iran.
Iran's naval presence in the Persian Gulf has therefore adopted the features of a guerrilla force. The so-called primitive nature of the Iranian tactic — where quantity outweighs quality — will continue to pose a challenge to the Fifth Fleet of the U.S. Navy.
Iran is not just more aggressive at sea; the Iranian Navy is indeed sailing farther afield in recent years, signaling the intention to expand its ability to operate both littoral and blue water.
Iran continues to declare its aims to enter the Atlantic Ocean, although, if materialized, it would largely be a symbolic sail. The Islamic republic has invariably asserted that it only uses its naval might for defensive purposes and that it carries a message of peace and friendship to other countries, but its vessels, often sailing under the flags of other countries, are also known to transported illicit cargoes.
Iran sees itself as the regional hegemon and its two naval branches are meant to support this impression as it continues to develop and improve its available methods and means of warfare.
To do so, Iran will need vast resources it doesn't yet have. Until it does, Iran is using other means against its enemies.
For example, it provides its proxies in the region with land-based, anti-missiles and other arms to impede their activity at sea. Only recently the Houthis fired several shore-to-sea missiles at U.S. and Emirati warships imposing the naval blockade on Yemen.
The Obama administration shied away from confrontation with Iran in land and at sea at almost any cost. America's credibility, image of strength and deterrence eroded due to weak responses to provocations and attempts to harm American forces.
The Trump administration should do more to counter the threat posed by Iran and use the naval arena, where it enjoys clear superiority, to check Iran.
"The Iranian regime, in my mind, is the single most enduring threat to stability and peace in the Middle East," Secretary of Defense-designate Gen. James Mattis said in in April. "Among all the issues facing us in the Middle East, I think Iran is actually foremost.
"And yet, at the same time, it appears here in Washington that we've forgotten how to keep certain issues foremost," Mattis said.
The firm tone of President-elect Trump and Mattis toward Iran may have already unsettled the ruling clerics in the Islamic republic.
During the election campaign, the president-elect, referring to a series of close encounters between the U.S. and Iran in the Persian Gulf, said, if the behavior repeats itself during his watch, the Iranians "will be shot out of the water".
The number of incidents between the U.S. Fifth Fleet and Iranian Revolutionary Guards Corps ships doubled in 2016 and Iran even took 11 American sailors into custody in January after they accidentally strayed into Iranian waters.
Yoel Guzansky is a research fellow at the Hoover Institution, a public policy think tank and research institution. Previously, Guzansky was in charge of strategic issues at Israel's National Security Council in the Prime Minister's Office, coordinating work on the Iranian nuclear challenge.
The views expressed by contributors are their own and not the views of The Hill.