He came up for parole again. Just like clockwork. Every five years. For the 13th time since he was convicted of the murder of Senator Robert F. Kennedy in 1968, Sirhan Bishara Sirhan went before the California Board of Parole again this week. Sirhan was sentenced to death in 1969 but his sentence was commuted to life in prison when the California Supreme Court invalidated all death penalties prior to 1972. Sirhan turns 62 on Sunday. He has spent the last 38 years behind bars and now resides in the California State Prison in Corcoran, also the home of another famous murderer from that era, Charles Manson.

Ask most people under 40 who Sirhan is and you will probably get a puzzled look. Sirhan shot Robert F. Kennedy just moments after the presidential candidate delivered his victory speech in the Ambassador Hotel’s ballroom on June 5, 1968. Kennedy had just won the last and largest primary in that volatile election year and was set to take on his greatest rival for the Democratic nomination, Vice President Hubert Humphrey, at the Chicago convention in August. Kennedy also won the smaller South Dakota primary that night. In political terms, Kennedy finally gained the momentum, even though he trailed Humphrey in delegates. Had that trajectory continued, Kennedy could have taken the Democratic nomination for president.

The Kennedy family in 1968 still had massive influence and contacts throughout the party, including heavyweights like Chicago Mayor Richard J. Daley, who controlled not just the huge Cook County vote, but who would also serve as host for the critical convention just two months ahead. There is a very good chance that Kennedy could have gone on to defeat Richard Nixon that November, becoming the nation’s 37th president. But of course, that is only speculation because Sirhan Sirhan changed the course of American history when he shot Kennedy that night in June – three times at close range, two shots in the back and one behind Kennedy’s right ear. Robert Kennedy died 25 hours later in a nearby hospital bed with his family around him. He was 42.

The country was numb at that point – barely five years after losing a beloved president, Kennedy’s older brother, John F. Kennedy, and just two months after Martin Luther King was gunned down on a hotel balcony in Memphis. It’s understandable that most Americans would concentrate that June on the shooting and not the shooter. But Robert Kennedy’s assassination was vastly different from all the others. This political killing was tied not to domestic issues or random insanity, but to the hatred of an American politician for supporting Israel.

Sirhan Sirhan is a Palestinian, born in Jerusalem on March 19, 1944. His parents immigrated to Los Angeles when he was a young boy. Rather than partake in what may have been the greatest economic opportunity in the history of man – Southern California in the 1950s – Sirhan’s family remained obsessed with Old World hatreds. From his diary entries, Sirhan was consumed by his hatred of Israel and its stunning victory in the Six Day War (which began on June 5, 1967 – one year to the day before the shooting). Just one week before the killing, Robert Kennedy strongly supported military sales to Israel in a nationally televised debate against Minnesota Senator Eugene McCarthy. Whether it was Sirhan’s obsession with the Six Day War, his hatred of the United States, Kennedy’s strong support of the Jewish state or all of the above, Sirhan Sirhan goes down in history as the first and only foreign terrorist to kill a major U.S. figure. In 1968, five years after the assassination of his brother, few Americans commanded more attention than Robert F. Kennedy. But 38 years later, the memory dulls, candidates and presidents have come and gone. Americans under 40 have difficulty grasping Kennedy’s significant influence at that place and time. And, of course, no one could foresee the hatred that spawned his killing would only intensify and lead to a long chain of terror.

But it should always be remembered that: 15 years before the bombing of the Marine barracks in Beirut that killed 241 U.S. servicemen … 17 years before the hijacking of TWA 847 where a U.S. sailor was beaten to death … 25 years before the first World Trade Center bombing killed six and wounded 1,000 … 28 years be fore the bombing at Khobar Towers in Saudi Arabia killed 19 U.S. servicemen … 30 years before the U.S. embassy bombings in Dar es Salaam and Nairobi killed 220 … 32 years before the attack on the U.S.S. Cole in Yemen killed 17 sailors … and 33 years before the September 11th attacks killed 3,000 in airplanes, the Pentagon, and the World Trade Center … there was a first act of Arab terrorism that changed the course of American history. Regardless of the professed reasons for these attacks – whether it be Palestinian liberation, Al Qaeda’s global Islamic strategy, or just a freelancer’s maniacal obsession – they all have one crucial common link: terror.

The California parole board denied Sirhan’s parole on Wednesday for the 13th time. A spokesperson for the Board of Parole hearings, Tip Kindel, explained that Sirhan is “very hostile. He hates Americans … He continues to pose a risk to public safety.”

Sirhan comes up for parole again in 2011, five years from now. Just like clockwork.

Mr. Kozak is a contributor to The New York Sun.