Isser Harel (; 1912 – 18 February 2003) was spymaster of the intelligence and the security services of Israel and the director of the Mossad (1952–1963). In his capacity as Mossad director, he oversaw the capture and covert transportation to Israel of Holocaust organizer Adolf Eichmann.

Harel was the only individual in the history of the State of Israel to hold a position that consolidated both internal and external intelligence responsibilities.

Biography Childhood and youth Isser Harel was born as Isser Natanovich Halperin in 1912 in the city of Vitebsk (in modern-day Belarus), then within the Pale of Settlement of the Russian Empire, as the fourth child to a wealthy Jewish family. His father, Rabbi Natan-Neta Halperin, was a graduate of the Lithuanian Volozhin Yeshiva, and his mother, Yocheved (née Levin), was a homemaker, the daughter of a wealthy local Jewish industrialist. His exact birthdate is unknown; it was recorded in his father's Talmud volume, but the book was lost due to the upheavals of the Russian Revolution and World War I. The Halperin family owned a vinegar factory in Vitebsk, a gift from his maternal grandfather, who had held a concession to produce vinegar in large parts of Tsarist Russia.

Whilst six years old, the Russian Civil War broke out, and Vitebsk changed hands several times between the Whites and the Reds. He once attended a speech given by Leon Trotsky in his city. The Soviet regime confiscated the family's property, and they suffered from hunger.

In 1922, the family left the Soviet Union and relocated to the city of Daugavpils in independent Latvia. On their way, Soviet soldiers robbed them of their remaining possessions. In Daugavpils, he received a formal education, completing elementary school and beginning high school studies. In his book Security and Democracy, he describes a significant event in the city related to Rabbi Meir Simcha of Dvinsk, who served as the local rabbi. He writes that during a particularly rainy winter, the local river overflowed, threatening to breach the dam and flood the city. Rabbi Meir Simcha prayed for mercy, and shortly afterward, the waters began to recede, saving the city.

As he grew older, his Jewish national consciousness awakened, and he joined a Zionist youth movement. At the age of 16, Halperin left for hachshara (agricultural training) in preparation for aliyah to Mandatory Palestine. During his year of training, he worked in agriculture, aspiring to join a kibbutz. In 1929, following the outbreak of the 1929 Arab riots, his group decided to expedite their immigration to Palestine to support the Yishuv. At 17, Halperin obtained forged documents that claimed he was 18, which allowed him to receive a certificate of immigration (certificat) from the British Mandate. In early 1930, he made aliyah, crossing Europe from north to south and boarding a ship in Genoa bound for Palestine. He carried a pistol, which he concealed in a loaf of bread.

In Mandatory Palestine

In Palestine, Isser Halperin joined the group from HaKibbutz HaMeuhad that founded Kibbutz Shfayim. Initially, he worked as a pioneer in the citrus orchards of the Sharon plain and in a packing house. During this time, he married Rivka, his kibbutz companion. In 1935, Halperin and his wife decided to bring their families to Palestine. Halperin took out loans to finance their immigration, and both families came to live with them in the kibbutz. He asked the kibbutz for help repaying the loans, but his request was denied. As a result, the three families left the kibbutz and moved to Herzliya. They lived communally in a dilapidated hut, earning their livelihood as packing house workers. Eventually, Halperin began working as a contractor installing irrigation pipes in orchards, and the family emerged from their financial difficulties. Halperin and Rivka had one daughter.

Intelligence in the Pre-State Era With the outbreak of World War II, Halperin felt he could not continue his profitable work while his friends enlisted in the British Army or the Palmach. In 1942, he approached the Haganah in Herzliya and volunteered. This was during the period when Erwin Rommel's German forces were advancing toward Palestine (a period known as the "200 Days of Dread"). The Haganah decided that priority should be given to the defense of the land and sent Halperin to a Haganah commander's course. Upon returning from the course, he was assigned to the coastal guard in British uniforms, but his main activity was within the Haganah's intelligence service, the Shai. Halperin was reassigned from the coastal guard after he assaulted a corrupt British officer who made antisemitic remarks. He was placed in the Jewish Settlement Police (the Notrim) while continuing his role in the Shai.

In 1944, Halperin was summoned by Israel Amir (Zabludovsky), the commander of the Shai, who informed him that he was being assigned to serve in the Shai headquarters in Tel Aviv. This marked the beginning of his long career in commanding positions within the intelligence services of the pre-state Yishuv and later the intelligence community of Israel.

Halperin began working at the Shai headquarters in Tel Aviv at the end of 1944, serving as the secretary of the "Jewish Department." The department was headed by Yosef Karo, and Halperin served as his assistant. The department's role was internal security, and it dealt, among other things, with gathering intelligence on underground movements that did not accept the authority of the national institutions, such as the Irgun and Lehi, as well as on the activities of communists. A few months after starting as the department's secretary, Halperin was appointed to head the department.

In 1947, Halperin name came to the attention of David Ben-Gurion. He was introduced to Ben-Gurion and reported on the activities of his department. During that meeting, Ben-Gurion decided to rename the "Jewish Department" to the "Internal Department." Halperin succeeded in his role and became an unofficial spokesman for the Shai. He maintained fair relations with members of other underground movements, who were under his department's surveillance.

At the Shai headquarters, Halperin earned the nickname "Isser the Small," both due to his short stature and to distinguish him from "Isser the Great," Isser Be'eri (Birenzweig), who joined the Shai headquarters in 1947 and was tall in stature. Be'eri later became the head of Israeli Military Intelligence, but was dismissed following the Ali Qassem Abed al-Qader affair.

In 1947, Halperin was appointed the commander of the Tel Aviv District of the Shai, responsible for gathering intelligence from Arab Jaffa. This was a challenging period for the Shai, following Black Saturday and due to the decline in the number of Arab informants, a result of the national awakening among Jaffa's Arabs leading up to the War of Independence. Halperin took steps to recruit new sources and succeeded in doing so. Shortly before the declaration of the State of Israel, Halperin deployed an Arab agent on a mission to Amman to assess Jordan's intentions and whether they planned to go to war. The agent reported that the Jordanians intended to join the war, and Halperin hurried to inform Ben-Gurion.

Intelligence in the State of Israel Upon the establishment of the State of Israel, Halperin was given the rank of Lieutenant Colonel, then one of the highest ranks, just below Colonel (the rank of Aluf-Mishneh was only added in 1950, and the rank of Tat Aluf was introduced only after the Six-Day War). He was appointed to head the "Shin Bet" (General Security Service), a branch of the IDF. (Later, the service became an independent organization outside the IDF framework, also known as the Shin Bet).

The service under Halperin's leadership had to be built from scratch, determining its principles, organizational structure, and methods of operation. One of the basic principles he established was that the employees of the organization had to be full-fledged government employees, with appropriate ranking, salary, and social benefits, without the special privileges and perks typically associated with secret service personnel in undemocratic countries. Another principle set by Halperin was that employees had to maintain a high moral standard, with no criminal background and no adventurist tendencies. This principle, he claimed, was not adopted by military intelligence at that time, leading to scandals such as the Avri Elad and Mordechai Kedar cases.

Halperin also decided to break down the political and party-based barriers that existed before the establishment of the state. He employed, without distinction, former members of the Haganah, Palmach, Irgun, and Lehi in the Shin Bet and later in the Mossad. This inclusive approach allowed individuals such as Yitzhak Shamir, a former commander of the Lehi and later Prime Minister of Israel, to be integrated into Israel's intelligence services. This policy contrasted with the prevailing sentiment of the time, expressed by David Ben-Gurion in his policy of "Without Herut and Maki", which marginalized members of the political right. Employing right-wing figures in government institutions was not common practice.

During the 1948 Arab–Israeli War, the Shin Bet was primarily engaged in internal security matters. After the war, the service expanded its operations to include counter-espionage and the monitoring of Israeli Arabs for intelligence purposes.

Involvement with Ben-Gurion and political surveillance At this time, Halperin grew closer to Prime Minister and Minister of Defense David Ben-Gurion. Much of the information he provided Ben-Gurion around 1951 pertained to subversive activities against the state. However, in addition to providing intelligence of national importance, Halperin also supplied politically charged information, including recommendations for actions by Mapai (Ben-Gurion's party) and details of developments within opposition parties.

In 1951, the Mossad for Intelligence and Special Operations was established, with Reuven Shiloah as its head. In September 1952, Shiloah resigned and suggested to David Ben-Gurion that Halperin Halperin (now known as Isser Harel) replace him.

Head of the Mossad On 22 September 1952, Harel was appointed head of the newly established Mossad. From his appointment until his resignation on 25 March 1963, Harel also held responsibility for the Shin Bet, where the head of the Shin Bet was subordinate to his directives. This dual role earned Harel the title "Mossad Chief" or "The Head of Israeli Security Services." To emphasize this hierarchy, the Mossad was officially referred to as the "Central Institute for Intelligence and Security" (later renamed the "Mossad for Intelligence and Special Tasks"). After Harel's resignation in 1963, the dual role was abolished and has never been reinstated. Isser Harel was the only individual in the history of the State of Israel to hold a position that consolidated both internal and external intelligence responsibilities, giving him unprecedented power. Harel participated in leadership meetings of the ruling Mapai party, where he would also report on the activities of opposition parties.

For eleven years, Harel served as the head of Israeli intelligence services, during which time the organizational structures and operational methods of the security services were formed and refined. These years also saw significant intelligence and security achievements. In 1953, the Shin Bet successfully exposed the right-wing extremist underground, leading to the prosecution of its members. However, some critics claimed that Harel exhibited authoritarian behavior and tended to bypass legal boundaries when necessary, as seen in the case of Operation Bren, where the body of an Israeli officer suspected of selling military secrets to Egypt was secretly disposed of following his accidental death during his arrest.