In the 1975 movie Jaws, the threat posed by a Great White shark to swimmers was only neutralized after aggressive action to confront it was taken.

In the Middle East, a similar threat to Saudi Arabia is posed by Iran’s mullahs, who seek to destabilize the region. Recognizing this threat must now aggressively be challenged, the Saudi Crown Prince has undertaken initiatives on both a domestic and international level seeking to stabilize the region and neutralize the Iranian threat.

As often occurs when a leader implements new policies, Prince Mohammed bin Salman (known as “MBS”) has generated supporters and critics by his actions. It is significant to note what he seeks to do today takes his country in the opposite direction taken by another Crown Prince 38 years ago.

In 1979, Saudi Arabia faced challenges on both an international and domestic level. The fact the mullahs took control of Iran with U.S. complicity, followed by Washington’s inaction after they seized the American embassy, caused the Saudis to worry whether we were folding up our protective umbrella. They understood back then that a Shiite bully had taken up residence in a predominantly Sunni neighborhood.

With Iran thus presenting a regional threat, a domestic crisis occurred in Saudi Arabia later that year, causing Crown Prince Fahd to take action. Extremist insurgents seized the Grand Mosque in Mecca — the world’s largest — calling for the overthrow of the royal family, the House of Saud.

The seizure, in part, was due to the government’s relaxation of fundamentalist beliefs opposing education for women, watching television, and seeking closer ties with the West. The terrorists were driven out after a two-week battle, but the Saudis sought to placate fundamentalist discontent by throttling back on reforms.

For years afterwards, as some U.S. Middle East experts noted, “We longed for the day when risk-averse Saudi leaders would take greater ownership in solving their domestic and regional security problems and reduce their dependence on the United States.” However, perhaps intimidated by Iran, the Saudis failed to do so.

But now, we fast-forward to present-day Saudi Arabia and a new Crown Prince. Although not yet born when the mullahs came to power, MBS, 32, has witnessed during his lifetime Iran’s hegemonic expansion, achieved at the expense of both Saudi and American interests in the region. For a quarter of that lifetime, he observed growing Iranian influence met only by U.S. complacency during an eight-year Barack Obama presidency. MBS undoubtedly saw Obama’s “see-no-evil” approach towards the mullahs as an utter failure, especially after he told the Saudis they must “share the neighborhood” with Iran.

Things normally move slowly in Saudi Arabia, which is what makes MBS an enigma. After he was named Crown Prince five months ago, he moved quickly to implement changes on both the domestic and foreign policy fronts. He has taken on the responsibility to create a united regional Sunni front to challenge the mullahs. And he has sought, once again, to fundamentally change his country by going back to earlier reform efforts. MBS has said Saudi Arabia must be modernized and that groundwork must be done to make it less dependent upon oil.

MBS appears to see in President Donald Trump as a kindred spirit — one who has indicated his support for the prince’s initiatives. MBS’s relationship with Trump indicates that he sees in him a leader willing to buck the era of Obama complacency, a leader willing to call a spade a spade, and a leader willing to act against a national security threat. Perhaps from MBS’s perspective, Trump’s election is a sign from Allah for the Saudis to take on a regional leadership role. In any event, it is a role he sees as absolutely vital in countering an Iranian threat that has gone unchallenged for far too long. Complacency has only made the mullahs more brazen, evidenced by Iranian missiles fired by Tehran’s proxies at U.S., Saudi and Bahraini targets.

Perhaps most surprising to Saudi observers was an anti-corruption initiative MBS undertook this month. He, like Trump, seeks to drain the swamp. He arrested or otherwise detained 200 people in a purge that netted eleven princes, several government ministers, and numerous wealthy businessmen. Additionally, over 1,700 bank accounts were frozen.

The purge sought not only to secure power for MBS but also to demonstrate his commitment to transform his country into a modern state. Doing so requires he crack down on corruption—even if it means removing the royal shield protecting Saudi elites. The sweep reportedly will reel in $800 billion for the treasury. That will buy MBS more time to explore ways of making Saudi citizens less dependent on welfare, which is costing the state $12 billion monthly.

Among those rounded up in the sweep was Prince Alwaleed bin Talal, believed to be worth $17 billion. Interestingly, he has had long-term ties to the Democratic Party, having been a major Clinton Foundation donor. Arrested as well was Osama bin Laden’s older brother who heads one of the world’s largest construction companies.

With “a-spade-is-a-spade” frankness, MBS called an unsuccessful missile attack against Riyadh by Yemen’s Houthi rebels “an act of war” by Iran. Then, in a surprise move during Lebanese Prime Minister Saad Hariri’s visit to Riyadh, the PM resigned (he has since rescinded his resignation). Questions remain whether Hariri acted independently or pursuant to MBS’s instructions designed to show that Hezbollah, Iran’s proxy army, is the real power in Lebanon. The latter possibility has caused Secretary of State Rex Tillerson to cross swords with President Trump by warning MBS not to interfere with Lebanon’s government even after Trump indicated he fully supported MBS’s actions to challenge Tehran’s mullahs.

There is no doubt MBS has entered into treacherous waters in confronting Tehran. Unfortunately, years of appeasing the mullahs have made his disruptive actions the last arrows in his quiver of options in a princely effort to save the Kingdom.

Lt. Colonel James G. Zumwalt, USMC (Ret.), is a retired Marine infantry officer who served in the Vietnam war, the U.S. invasion of Panama and the first Gulf war. He is the author of “Bare Feet, Iron Will–Stories from the Other Side of Vietnam’s Battlefields,” “Living the Juche Lie: North Korea’s Kim Dynasty” and “Doomsday: Iran–The Clock is Ticking.” He frequently writes on foreign policy and defense issues.