One-hundred years ago this month, the Ottoman Turks, then in control of Palestine, rounded up and destroyed a Zionist intelligence network that made a decisively important contribution to the British invasion and liberation of Palestine. This is the group’s story.

The Great War of 1914-18—now called World War I—ended the Ottoman empire’s control of the Near East and allowed both Zionism and Arab nationalism to advance. After Britain invaded Palestine in 1917, its officials would run it for three decades and relinquish it only under pressure. Because they exerted themselves to hold on to the Holy Land, one might suppose they had jumped at the opportunity to conquer it.

In fact, they hadn’t.

The government of Prime Minister Herbert Henry Asquith, which took Britain into the Great War, had little to no interest in Palestine. It focused chiefly on Europe’s Western front and, in line with liberal principles, opposed enlarging the British empire at all. Even after the Ottoman empire joined with the Central Powers and became an enemy, Asquith’s War Office begrudged resources for efforts against the Turks. It planned to defend Britain’s control of Egypt but to let others fight in the Near East, which top British generals deprecated as a sideshow.

But bad war news—the Gallipoli defeat, exasperating stalemate on the Western front and astounding casualties at the Somme and elsewhere—toppled the Asquith government. In December 1916, David Lloyd George replaced Asquith as prime minister and changed the Allied war strategy. For him, routing the Turks was the key to victory. His war cabinet ordered the invasion of Palestine and on November 2, 1917 issued the Balfour Declaration.

That official endorsement of Zionism ignited a firestorm of controversy that hasn’t subsided for a century. Debated intensely at the time, it still elicits angry denunciations, most vocally in this anniversary year by Palestinian Arab officials. Making sense of it requires understanding why British leaders, fighting for the life of their empire in the Great War, did what they did.

When they promised to support a national home in Palestine for the Jewish people, British leaders were not thinking narrowly about Palestine and only Palestine. Their strategic perspective took in the entire postwar Middle East (which itself was but one of many regions demanding British attention). They also envisioned dealing generously with the Arab people, who would be put on the path to national self-determination in several large countries. Indeed, even though most Arabs had aligned themselves with the Allies’ Turkish enemies, they would get control of almost all the land they claimed. The Arabs in Syria, Iraq, Arabia, and elsewhere would emerge from the war far better off than some of the peoples of Europe, especially those on the losing side.

True, the Arabs in Palestine would eventually live as a minority in a democratic, Jewish-majority country, and that was an imposition—but, as Lloyd George saw it, a relatively minor one. During World War I, no one thought of the Arabs in Palestine as a distinct people entitled to national self-determination on their own—not even the Palestinian Arabs themselves. Anti-Zionists today say that the Arabs’ relegation to minority status was a unique collective misfortune, but the British authors of the Balfour Declaration knew it wasn’t. They were committed to protecting the individual rights of the Arab minority in Palestine just as they intended to do for minority peoples in newly delineated states throughout Europe.

Lloyd George’s embrace of Zionism reflected a moral impulse to succor the Jews after centuries of mistreatment. It was also strategic, part of a worldwide effort to win public opinion over to Britain’s side in the war. Since the war’s outbreak, many Jews had sympathized with the Central Powers because Russia, the world’s most anti-Jewish country at the time, was one of the Allies. Lloyd George saw it as a wartime necessity to give Jews everywhere, and especially in Russia and America, an interest in Allied victory. In addition, serving as the Zionists’ protector would help Britain to justify retaining control over Palestine as part of the postwar peace arrangements.

Those were the outlines of the bigger picture—why the Balfour Declaration fitted into British strategy. There are also noteworthy smaller pictures: in particular, how British policy makers learned about Zionism from Jews who contributed courageously and valuably to the Allied war effort.

The story of Aaron Aaronsohn and his NILI spy network is a significant, if generally underappreciated, part of the history of the Great War and the Middle East.

In the summer of 1917, Lloyd George had ample motive to press for a fast, morale-boosting victory. The Allied war against the German, Austro-Hungarian, and Ottoman empires was continuing to produce enormous losses with little hope of a breakthrough on the Western front. The British war cabinet, considering opportunities in the Near East, debated whether to make a pro-Zionist statement. General Edmund Allenby had just been given command of British forces in Egypt. In June, meeting him for the first time, Lloyd George exhorted the general to deliver “Jerusalem by Christmas.”

Allenby considered invading Palestine by marching his forces from Egypt, up the coast, through Gaza. He faced the same problems that had stymied his predecessor, Sir Archibald Murray: water for his troops, and Gaza’s daunting fortifications. His initial plans received poor reviews from the Imperial General Staff, whose chief remained opposed to the very idea of a Palestine campaign and declared Allenby’s ideas too risky and not worth the expense.

To overcome his problems, Allenby knew that he had to find better intelligence. His best source emerged in the form of a Jewish Zionist named Aaron Aaronsohn.

Aaronsohn (1876-1919) was one of three Zionist mavericks—the others were Ze’ev Jabotinsky and Chaim Weizmann—who eagerly offered valuable help to the Allied war effort even as the British were pleading with a hesitant Sharif Hussein of Mecca—later famously assisted by T.E. Lawrence (“of Arabia”)—to start an Arab revolt against the Turks. In siding with Britain, these three Zionists put themselves at odds with official Zionist policy.

The leadership of the Zionist Organization, headquartered in Berlin, had resolved on wartime neutrality because the war’s outcome was uncertain and, if their organization backed the Allies, the Ottomans might crush the Jewish community in Palestine. Aaronsohn, Jabotinsky, and Weizmann calculated differently, however. As they saw it, the Turks were likely in any case to deal harshly with the Palestinian Jews, and a British-controlled Palestine was Zionism’s best hope.

To advance that hope, Aaronsohn organized a spy network for Britain behind Turkish lines. Known as NILI—an acronym for the biblical Hebrew phrase netsaḥ yisrael lo y’shaker (the Champion of Israel will not deceive [1Samuel 15:29])—it gathered rich information in the face of fearsome danger. Everyone involved risked death, and the key personnel were Aaronsohn’s own family members. They became, in the later words of their British liaison officer, William Ormsby-Gore (a future colonial secretary), “the most valuable nucleus of our intelligence in Palestine.”

Born in Romania, Aaronson had arrived in the Holy Land with his parents at the age of six. There they moved into a new Jewish agricultural settlement, Zichron Yaakov, supported by the French Jewish financier Baron Edmund de Rothschild. The young Aaronsohn developed Jewish nationalist fervor and an intense love of the land. A stocky teenager, he studied farming for two years in France and on his return home devoted himself to research. On horseback, often alone, garbed in a traditional Arab coat, he explored the terrain, cataloguing minerals, collecting plant samples, and identifying water sources.

In short order he became the world’s leading expert on Palestine’s natural history. Having won a scholarly reputation, he was urged by botanists abroad to take on a challenge that had eluded scientists for years: finding a living sample of the grain called wild emmer—triticum dicoccoides—also known as wild wheat. This was the plant that had made the land of Israel a breadbasket of the ancient world. Grafting it, agronomists theorized, could revolutionize food production in hot, arid places like the American southwest.

On a spring day in 1906, in the crevice of a rock in an orchard in Galilee, Aaronsohn spotted a single ear of the long-sought plant. After vainly combing the vicinity for more, he rode on horseback to Mount Hermon, and there his acute eye recognized the marvel of a blooming field of wild emmer.

The botanical world thrilled to the news. A U.S. Department of Agriculture official named David Fairchild requested samples and invited Aaronsohn to America. Of their first meeting, Fairchild wrote:

I soon discovered that I was in the presence of an extraordinary man. Although Aaronsohn had never been there, his knowledge of California almost equaled his knowledge of Palestine. No foreigner had ever been in my office who had so keen an understanding of the soils, climates, and adaptability of plants to their environment.

For four months, Aaronsohn lectured throughout the American West. The University of California at Berkeley offered him a professorship, but he passed it up. What he wanted was to establish a research facility in Palestine.

With backing from prominent American Jewish philanthropists, Aaronsohn set up his research station in 1910 in Atlit, just south of Haifa. After the Great War began in the summer of 1914, it became the base of operations for his NILI spy network.

Aaronsohn long knew that the Turkish authorities opposed Zionism. Once the war started, he saw them as not only hostile but dangerous. In his view, Palestine’s Jewish community, known as the yishuv, was as vulnerable as the Armenians in Anatolia, whom the Turks accused of colluding with Russia and massacred in great numbers. Djemal Pasha, commander of the Fourth Ottoman Army and the effective dictator in Syria and Palestine, accused the local Jews of disloyalty, and in December 1914 expelled about a thousand from the Holy Land. Among them were David Ben-Gurion (the future Israeli prime minister) and Yitzḥak Ben-Zvi (the future Israeli president)—both of whom, as it happened, had been trying to organize Palestinian Jews to fight in support of Turkey.

For years, Aaronsohn had fantasized the takeover of Palestine by a liberal Western power favorable to Zionism. When the war made this a realistic possibility, he decided to help the British, who needed detailed information on the Ottoman army. Obtaining it would require him to win the trust of senior Ottoman officers, all the way up to Djemal Pasha—no easy task.

A plague of locusts provided his chance. Like a green and black river, a vast mass of the deafening and voracious pests inundated Palestine in March 1915, devastating food supplies. Aware that Aaronsohn headed a nearby agricultural research station, an alarmed Djemal summoned him and sought his help against the locusts, hinting with grim playfulness that a refusal would have consequences: “What would you say if I ordered you to be hanged?” The brazen, burly Aaronsohn answered: “The weight of my body would break the tree, and the noise would be heard in America.” Djemal knew of Aaronsohn’s connections with officials of the then still-neutral United States, which was being courted by all sides.

By agreeing to organize war on the locusts, Aaronsohn could survey Palestine and Syria cloaked in Turkish military authority. Soon he had accumulated not only a lifetime’s store of knowledge of Palestine’s topography, geography, climate, and resources, but also current data on the Ottoman army’s order of battle.

The next challenge was creating a link with British intelligence. In July 1915 Aaronsohn put his brother Alexander and sister Rivkah, each provided with a forged passport, on an American ship sailing from Beirut. They debarked in Egypt, where Alexander, after much trouble, wangled a meeting with a British intelligence officer who dismissed his information as worthless.

Aaronsohn tried again: another forged passport, another ship to Alexandria. This time the traveler was Avshalom Feinberg, Rivkah’s fiancé and Aaronsohn’s best friend. Feinberg had the good fortune to connect with a different intelligence officer, who received his report appreciatively and arranged for British ships in the Mediterranean to communicate with the Jewish spies in Palestine by means of light signals and a rowboat. The system worked at first, but later failed due to human error.

Reports of Ottoman mass expulsions and killings of Armenians continued to reach Aaronsohn in 1916. He became increasingly fearful for the yishuv and saw it as urgent to connect reliably with British intelligence. British officials remained uninterested in invading Palestine, but he hoped his information on the land’s weak defenses would draw them in. He resolved to travel to England himself. To allay Turkish suspicions, he spread a false story that he had discovered a new type of oil-rich sesame seed with great economic potential—for which, he told Turkish authorities, he needed to consult botanists in Germany. Via Beirut, Damascus, and Istanbul, he arrived in Berlin, where he again invoked the bogus seed to win permission to cross into neutral Denmark for scientific meetings.

In Copenhagen, Aaronsohn slipped clandestinely into the British embassy, introduced himself to a senior diplomat, and disclosed the Palestine spy network, including verifiable details about the abortive connection with British officers in Egypt. The two agreed on a plan to get Aaronsohn to London without risking Turkish retaliation against his family and the rest of the NILI network. Aaronsohn first used his old contacts to obtain a U.S. Department of Agriculture invitation to visit the United States. Then he left Copenhagen by ship to Scotland on the way to America. In Scotland, by prearrangement, British authorities seized him and pretended to accuse him of being an Ottoman spy—a dramatic piece of insurance in case Turkish authorities learned he was in Britain.

From Scotland, he was brought to London for questioning. Remarkable for a self-possession that often came across as arrogance, he showed intelligence officials there no more awe than he had in Djemal Pasha’s presence. A brief initial meeting with a low-ranking Turkey expert led to extended conversations with the chief of military intelligence in the war office and with the influential parliamentarian Sir Mark Sykes (who had negotiated the Sykes-Picot agreement on postwar control of Arab lands).

The intelligence chief appreciated that Aaronsohn was a man of courage, physically strong, modern and secular but proudly Jewish, who knew how to farm and who without talking of money or other rewards was volunteering to serve Britain’s war effort despite all of the military and political uncertainties ahead. The chief lost no time in composing a 38-page report on Aaronsohn’s information, arguing that the Palestinian Jewish spy network would remain valuable.

Aaronsohn similarly wowed Sykes, who arranged to meet with him three times within ten days and invited him to his home. In their talks, Aaronsohn helped Sykes see that Zionism was both practicable and advantageous to Britain. Soon afterward, Sykes began the consultations with other Zionists in Britain that would result in the Balfour Declaration.

Aaronsohn insisted on personally supervising the link between British intelligence and his team in Palestine. He asked to be sent to Egypt and, in time, shipped out for Port Said. While he was still at sea, the British government changed hands.

Paying the price for lack of battlefield success, Prime Minister Asquith had been forced to resign. Lloyd George, who organized Asquith’s downfall, took over the premiership on December 7, 1916 with, as we have seen, a radically different war strategy that stressed the importance of defeating Turkey as the means to win the whole war. For the new strategy to work, Britain would have to conquer Palestine.

Aaronsohn thought his prayers had been granted. In Cairo, he could be the right man at the right place at the right time.

During his absence from Palestine, his sister Sarah had taken charge of the NILI spies. She managed to pass reports to him across Turkish lines, but some of the NILI operatives were killed or badly wounded in the process. As the group’s losses increased, so did Aaronsohn’s resentment that his British colleagues in Cairo showed him little appreciation and even some distrust. “Our conversation was positively maddening,” he wrote in his diary after meeting his young intelligence control officer. “More than twenty times I felt like throwing up to their face what I thought of their complete and irremediable inability to understand the situation.”

But appreciation of the Jewish spies increased when Aaronsohn connected with William Ormsby-Gore, another British intelligence officer, who enthusiastically sent home NILI’s reports on Turkey’s resources and vulnerabilities. Aaronsohn educated him about the Jewish national cause, and Ormsby-Gore, well-connected and well-regarded, helped Aaronsohn win trust from the leadership in Cairo.

To the British, one of Aaronsohn’s off-putting crotchets was his theory that water flowed in abundance under the deserts of Sinai and southern Palestine. Mocking the assumption of British officers that they needed to build a railroad and pipeline to bring water from Egypt to Palestine for their invasion force, he cited the 1st-century-CE historian Flavius Josephus, author of The Jewish War, who wrote of gardens in areas that were now desert. Those areas must still have water beneath the ground, Aaronsohn insisted, claiming that current rock formations supported his theory.

The story sounded preposterous, but Aaronsohn established his point. As the British intelligence officer Basil Thomson later reported:

Our troops in Palestine had been drawing their water from Egypt and carrying it to Palestine by rail in tanks. Aaronson bullied the officer commanding the Royal Engineers into sending to Egypt for boring machinery, undertaking that water would be found at a depth of 300 feet. When an experimental shaft was sunk, water gushed up from a depth of 295 feet.

A later historian would write, “No unprejudiced reader can doubt that intelligence about water [was] the vital clue to Allenby’s victories.”

One of Allenby’s major challenges was to plot an invasion route. Not surprised that the previous commander, General Archibald Murray, had twice failed to penetrate Palestine through Gaza, Aaronsohn came up with less conventional and more promising ways into the Holy Land. At first, he promoted a naval landing on the lightly defended northern coast, around Haifa. But after the Gallipoli disaster, top British officials wouldn’t hear of another amphibious operation. They were determined to enter from the Sinai, so Aaronsohn urged them to invade inland toward Beersheba rather than through a standard up-the-coast move. Gaza, he argued, would fall more easily if it were outflanked from the east.

At long last, on July 17, 1917, he received an audience with Allenby himself. The general “greeted me exceedingly well,” Aaronsohn noted in his diary, “He said he had been informed that I was thoroughly acquainted with the country and asked me for my views.” Among the many topics they covered were the enemy’s commanders. Djemal, Aaronsohn said, was vain, superficial, and “absolutely null from a military standpoint,” but the German Kress von Kressenstein was “a dangerous opponent . . . likely to do the unexpected.” Allenby “made an excellent impression,” and Aaronsohn was “delighted with the interview.”

Although Allenby’s original intention had been to follow the coast and hit Gaza from the southwest, just as Murray had done, he came around to Aaronsohn’s view and devised a campaign that opened with a feint toward Gaza but a main thrust toward Beersheba. It succeeded brilliantly and, when the time came, Gaza fell to a blow from the east.

Britain’s pro-Zionist Balfour Declaration evolved through multiple drafts over the summer and into the fall of 1917. Instrumental in moving it forward were Mark Sykes and William Ormsby-Gore. They were at this time two of the three assistant secretaries of the war cabinet. Each said he had come to admire Zionism through regard for Aaron Aaronsohn. It was a remarkable coincidence that these two men, both schooled on the Jews and Palestine by Aaronsohn, found themselves as colleagues in the secretariat of the war cabinet at this crucial moment in the history of the Jewish nationalist cause.

As it happened, however, just when Britain’s leaders were deciding how to frame the declaration, Turkish officers succeeded in destroying Aaronsohn’s intelligence network.

The beginning of the end for NILI was a wayward carrier pigeon. Bearing a coded message, the bird left the NILI base in Atlit and landed on September 4, 1917 in a nearby town at the home of a Turkish officer. That mishap, followed two weeks later by the capture of a Jewish spy trying to cross from Palestine to Egypt, allowed the Turks to unravel the network. Turkish forces arrested Sarah and her father in their home and tortured them for information. A local Jewish physician, Dr. Hillel Joffe, who treated the two recorded that the father “had been beaten mercilessly. His legs were swollen and blue, he breathed with much difficulty, but he was holding out bravely.” As for Sarah, she “showed the marks of whipping on her legs and her waist.”

During two more days of interrogation, Sarah was forced to witness her father’s abuse, as her torturers further whipped and scalded her and crushed her fingers but failed to extract any secrets. Sarah managed to retrieve a gun hidden in her house and shot herself through the mouth. She died in agony four days later, at the age of twenty-seven.

British intelligence learned of NILI’s demise—and of Sarah’s fatal steadfastness under torture—in mid-October. Away from Cairo on travel, Aaronsohn received the news a few weeks later. Devastating as the loss was, there was some consolation in NILI’s having already aided Allenby and advanced the Zionist cause—militarily against the Turks, and politically with the British.

In November 1917, the British issued the Balfour Declaration. Five weeks later, well before Christmas, General Allenby’s forces captured Jerusalem. The British army went on the next year to liberate the rest of Palestine and to end 400 years of Turkish ownership of the Near East. Turkey promptly quit the war and, less than two weeks later, Germany surrendered unconditionally.

In the assessment of Britain’s wartime chief of military intelligence, Major General George MacDonough, Allenby’s ability to carry out his “daring” campaign in Palestine without “unwarranted risks” owed much to NILI: “Allenby knew with certainty from his intelligence of all the preparations and all the movement of his enemy.” His words were validated by Allenby’s deputy military secretary, Raymond Savage: “It was very largely the daring work of young spies, most of them natives of Palestine, which enabled the brilliant Field-Marshal [Allenby] to accomplish his undertaking so effectively.”

Aaron Aaronsohn died in a plane crash in 1919. Allenby’s own posthumous, handwritten tribute credited him as “mainly responsible for the formation of my Field Intelligence Organization behind the Turkish lines.” His death, wrote Allenby, “deprived me of a valued friend and of a staff officer impossible to replace.”

When Ormsby-Gore informed the Foreign Office that NILI was “admittedly the most valuable nucleus of our intelligence in Palestine during the war,” he added: “In my opinion, nothing we can do for the Aaronsohn family will repay the work they have done and what they have suffered for us.”

A NILI Group Reading List

• Aaronsohn, Alexander. With the Turks in Palestine (1916)
• Dugdale, Blanche. Arthur James Balfour: First Earl of Balfour, 2 vols. (1937)
• Engle, Anita. The Nili Spies (1959)
• Falls, Cyril. Military Operations Egypt & Palestine: From June 1917 to the End of the War, 2 parts (1930)
• Florence, Ronald. Lawrence and Aaronsohn: T. E. Lawrence, Aaron Aaronsohn, and the Seeds of the Arab-Israeli Conflict (2007)
• Fromkin, David. A Peace to End All Peace: Creating the Modern Middle East, 1914-1922 (1989)
• Gardner, Brian. Allenby of Arabia: Lawrence’s General (1965)
• Goldstone, Patricia. Aaronsohn’s Maps: The Untold Story of the Man Who Might Have Created Peace in the Middle East (2007)
• Halkin, Hillel. A Strange Death: A Story Originating in Espionage, Betrayal, and Vengeance in a Village in Old Palestine (2005)
• Katz, Shmuel. The Aaronsohn Saga (2007)
• Leslie, Shane. Mark Sykes: His Life and Letters (1923)
• Lloyd George, David. Memoirs of the Peace Conference, 2 vols. (1939)
• Lloyd George, David. War Memoirs, 6 vols. (1933)
• Savage, Raymond. Allenby of Armageddon: A Record of the Career and Campaigns of Field-Marshal Viscount Allenby (1926)
• Schneer, Jonathan. The Balfour Declaration: The Origins of the Arab-Israeli Conflict (2010)
• Stein, Leonard. The Balfour Declaration (1961)
• Earl of Oxford and Asquith. [Herbert Henry Asquith]. Memories and Reflections, 1852-1927, 2 vols. (1928)
• Thomson, Basil. The Scene Changes (1937)
• Verrier, Anthony, ed. Agents of Empire: Anglo-Zionist Intelligence Operations 1915-1919 Brigadier Walter Gribbon, Aaron Aaronsohn, and the NILI Ring (1995)
• Wavell, Archibald. Allenby: A Study in Greatness: The Biography of Field-Marshal Viscount Allenby of Megiddo and Felixstowe (1941)
• Weizmann, Chaim. Trial and Error: The Autobiography of Chaim Weizmann (1949)