A retired Navy SEAL whose brother was killed by Hezbollah terrorists expressed relief when he heard that Hassan Nasrallah was killed.

“When the sun went down yesterday, the world was a better place with Nasrallah not in it,” Kenneth Stethem told The Post on Saturday, less than 24 hours after Nasrallah, 64, was killed in an Israeli airstrike on a Beirut suburb.

“Ever since [Hezbollah’s] inception in 1982, Nasrallah and others like him have caused much death and destruction,” he said.

Hassan Nassrallah was confirmed dead in Lebanon on Friday. AFP via Getty Images

Stethem would know: His brother, Navy diver Robert Dean “Robbie” Stethem, was killed by Hezbollah terrorists during the June 1985 TWA Flight 847 hijacking.

Robbie, 23, was returning from an assignment in Greece when the plane was hijacked by a pair of terrorists who demanded the release of 766 Palestinian and Lebanese inmates held in Israel.

The hijackers initially flew the plane to the Beirut airport, where an “enraged terrorist” beat Robbie before fatally shooting him in the head and tossing his body onto the tarmac, according to the US Navy Memorial. 

His face and body were reportedly so badly mangled that he could only be identified by his fingerprints.

Robert Dean Stethem was killed on June 15, 1985. US Dept of Defense

“I remember when they came to the door and told us. The sound that came from [our mother] sounded like an animal that had just been hit by a car. Never, never heard screams like that before or after,” Kenneth Stethem told The Post of the moment the family learned their son and brother had been murdered.

Stethem planned to break the news about Nasrallah’s death to his father, now 88, on Saturday.

When they last spoke two days ago, as Israel was bombarding Hezbollah, Stethem said he told his father, “Lady karma doesn’t forget, and tonight in Israel, the same people responsible for killing Rob are hearing bombs go off all around them.”

“He’s going to be grateful that [Hezbollah] was damaged as badly as they were damaged,” he told The Post of how he expected his dad to respond to the update.

Stethem’s mother died two years ago, but “she would be very grateful for what the Israelis had the courage to do,” the brother said.

The family of Robbie Stethem at his burial at Arlington Cemetery. Getty Images

Even though Hashem Safieddine is expected to take his cousin Nasrallah’s place as the head of Hezbollah, Stethem predicted that the decimated terror group will have difficulty reorganizing.

“Iran better be careful because Nasrallah didn’t trust anybody,” he claimed.

“Not only is he gone, without any mentees, but his general staff and staff below that is gone. So Iran should carefully choose their next actions, because they see that Israel will not stop until they cut the head off of this snake.”

President Ronald Reagan and First Lady Nancy Reagan laying a wreath on Stethem’s grave. Getty Images

“Terrorism has grown into the danger it is because we never formulated an effective policy against it,” Stethem added.

He referred to an Albert Einstein quote that typically reads, “The world is a dangerous place, not because of those who do evil, but because of the people who don’t do anything about it.”

“If you don’t take care of something when it’s a small problem, it grows into a big problem and grows chronic and then it can grow terminal,” Stethem noted.

 “We don’t wish harm on anyone,” he said of his family, which includes two other surviving siblings. “But those responsible need to be accountable.”