On November 2nd 1917, the Balfour Declaration was announced, according to which Britain would support the foundation of a national home for the Jews in Israel and even acknowledge the Zionist movement which represented these aspirations. About a month after the declaration, Israel was conquered by Britain and General Allenby entered Jerusalem in a parade. He was welcomed by the Jewish community for they understood that a Jewish state would soon be founded in Israel. The British authority center was established in Jerusalem.
The Arabs in Israel did not favor the Balfour declaration and the British intention to help the Jews, and so they began with political pressure that manifested in riots. In 1920-1921, Arab gangs began attacking Jewish settlements, beginning with the Galil area: Metula, Tel-Chai etc... These were shortly followed by attacks on Jerusalem: Six Jews were killed and around 200 injured, possessions were plundered and Synagogues burnt. Arab and British officers joined in with the latter attack. Only after three days did the British army intervene, and yet the blame for the riots fell on the Jewish community and many were arrested. As a result of these incidents, it was understood that it was impossible to depend on the British, and the Jews must defend themselves. This decision brought about the foundation of the "Hagana" organization. The organization created an internal defensive alignment in every Jewish settlement, in case of an attack.
After a few quiet years, in 1929, the Arabs felt threatened on account of the growth of the Jewish population and the number of Jews praying at the Western Wall. On the 23rd of August 1929, a Jewish demonstration for their freedom of religious ritual at the Western wall took place there. The Arabs arrived armed with clubs and knives and attacked the Jewish neighborhoods in Jerusalem. The riots continued the next day (Saturday, August 24th) in Hebron, where around sixty-seven Jews were murdered and their homes plundered. The result was the erasure of the Jewish community in Hebron, which had been settled there for hundreds of years. The Jews of Safed and Gaza were also damaged by the attacks. On the other hand, the Jews of Tel-Aviv and Haifa were able to push back the Arabs' attacks with the aid of the "Hagana" activists.
Consequent upon these events, in 1931, a group of activists left the "Hagana" and founded a new organization- The National Military Organization- IZL (Irgun Zvaei Leumi), and they claimed that the time had come to respond to attacks with aggression. The IZL activists initiated operations and ambushes outside of the Jewish settlement fence, a thing that had not been done beforehand.
On the British part, the "White Books" were being published- books of rules and restriction for the Jews , that decreased the amount of land that the Jews were permitted to purchase and the amount of Jews permitted to enter the country, because of heavy pressure coming from the Arabs. These books refuted all that was said in the Balfour declaration. Even greater pressure on the British came in 1936-1939, when the "Big Arab Rebellion" began. During these years, British food and ammunition convoys were attacked and the British governor was murdered in the Galil. In the attacks on the Jewish settlements, over eighty Jews were murdered, three hundred and nine were injured, and nineteen schools, nine nurseries, orphanages and three old age homes were attacked. Three hundred and eighty trains and buses were ambushed and around seventeen thousand dunams of land were destroyed. Because the Arabs stopped the farming, the domain was developed by the Jews, likewise, the "Hagana" changed their course of action and the organization founded a new portable unit called the "Noddedet" (the "Wanderers") which developed into "Plugot Hasade" (the "Field Companies") who protected the settlements from the Arab gangs even before their arrival and performed ambushes, chases and raids on the rioter's bases. Simultaneously, a collaboration began with the British by founding the "Plugot Halayla Hameyuhadot" ("The Special Night Company") which was trained by Major General Orde Wingate, who was nicknamed "the friend", and which performed hidden ambushes and raided Arab gang bases. In addition to the night companies, Jews were drafted to the Notrim unit- Jewish guards in the British police force- that helped defend the Jewish settlements. The community reacted to the incidents not only on the defense level, but also on the settlement level, and in that era the "Tower and Barrier" settlements were established.
Following the breakout of the Second World War, David Ben-Gurion cried out to the Jews to join the British army and help with the struggle against the Nazis. A group of IZL members saw this as an opportunity to act against the British; they left the IZL and founded yet another organization, the Israel Freedom Fighters ("Lochamei Cherut Yisrael- Lehi"). Their purpose was to hurt the British in Israel while they were busy with the war in Europe so that they would understand that Israel was not their land.
At the end of the Second World War, since the British had worsened the laws against the Jewish community and did not allow holocaust survivors and Jewish refugees from other countries (Morocco, Yemen…) to enter Israel, it was clear that the Balfour Declaration would not be realized without a struggle. It was decided to unite the three underground organizations and so the "Jewish Resistance Movement" was established. The idea was to work together against the British in order to banish them form Israel. The new movement was disassembled after the operation in the King David Hotel in Jerusalem, in which the southern wing was being used as headquarters by the British administration. The IZL activists dressed up as workers and entered the kitchen on the ground floor. They carried pitchers of milk containing 350 kilograms of explosives. After a few hours, at 12 o'clock, the IZL activists announced an upcoming explosion of the hotel, but the recipient of the message did not evacuate a soul from the wing. At 12:30 a huge explosion destroyed the entire south wing of the King David Hotel. 91 people were killed in the explosion: 28 British, 41 Arabs, 17 Jews and 5 hotel guests. It took the British army engineers two days to extract the bodies from the rubble. 476 people were injured as a result of the explosion.
Following this event, the "Jewish Resistance Movement" was disassembled and each underground organization continued with its own activities. On November 29th, the UN decided to end the British mandate in Israel, and so the country was divided into two parts: an Arab portion and Jewish portion. Jerusalem (with its surroundings) was declared a territory subjected to international supervision. The Jewish institutes accepted the division in order to allow the hundreds of thousands of Jewish refugees imprisoned in camps in Cyprus, Atlit, and those abroad to become acclimatized in Israel. The Arabs, on the other hand, did not accept the decision, and one day later, they began attacking the Jewish settlements. The British were concentrating on their evacuation and barred unrestricted immigration to Israel, forbade entry of arms, holding arms and Jewish military deployment. During the battles between the forces there was a focus on three fronts; mixed cities like Jerusalem, Tiberius and others, defending isolated settlements, and fighting on the movement routes.
On the 10th of March 1948, the Defense General Staff declared a master-plan called Plan D (Tohnit Dalet), which was the first strategic plan in the War of Independence. The plan outline was as such: conquering all the territory that was allocated to the Jews in the UN decision and the clusters of settlements outside this territory and also territories controlling the invasion routes, which they anticipated the Arabs to take.
The big operation that was conducted in the frame of Plan D was the Nachshon Operation. The target was to breach the route leading to Jerusalem. A number of brigades participated in this operation, these operated in coordination with the regular army and were equipped with rifles and machine-guns that arrived on the eve of the operation in a large delivery from Czechoslovakia. During the operation, convoys of food and supplies were transferred to Jerusalem. The Nachshon operation was the turning point in favor of the Jewish community in the war with the Israeli Arabs. Following it, the Harel Operation, to transfer a convoy of hundreds of trucks to Jerusalem on the eve of Passover, and the Maccabi Operation, which failed, to conquer Latrun and broaden the path to Jerusalem. At the same time, the attacks by the Arab Rescue Army (Arab volunteers commanded by Paozi El Kaokji, who came from Syria in aid of the Israeli Arabs) were warded off by the Jewish forces at the Mishmar Haemek Kibbutz. Druze forces were also warded off at the Ramat Yonatan Kibbutz, and as a result, the Druze soldiers agreed to assist the Hagana forces in battle.
Up until the Declaration of Independence, Jaffa, the Arab parts of Tiberius, Haifa, Tsfat and tens of Arab villages were conquered by the Jewish forces, and the Israeli Arabs began to escape, thus becoming refugees. In the mist of May, the city of Acre was also conquered. Although Plan D had great accomplishments, there were also many scathing failures. The Etzion bloc was attacked and surrendered one day before the Declaration of Independence. Har Tov was evacuated, as well as the settlements of Atarot and Navve Ya'akov in North Jerusalem. Furthermore, the Beit Ha'arave settlement in the Dead Sea area was evacuated. The success of Plan D situated the Jewish community in an improved strategic position in preparation for the Declaration of Independence and the invasion of the Arab countries.
On the 14th of May 1948, David Ben-Gurion announced the foundation of the state of Israel. Devoid of hesitation, five Arab armies invaded: Syria, Lebanon, Jordan, Iraq, and Egypt and attacked the state which had just been established.
During the first month, the Egyptian army besieged the Negev. In the Jerusalem sector, the Jordanian army conquered the Etzion bloc, Atrot, Nevve Ya'akov, the Haradar hill, Sheik-Jarrach, the Mount of Olives, Augusta Victoria, and the entire old city. The Iraqi army conquered the entire Samaria Mount. The Syrian army conquered Mishmar-Hayarden, while the Lebanese and the "Rescue Army" focused on the mountainous Galilee. During the war, on June 1st 1948, the Hagana organization became the Israeli Defense Force (Tzava Ha hagana Leyisrael). After two months, a let-up began in the fighting which was utilized for military deployment.
The War of Independence did not end with a peace treaty; however, a cease-fire treaty was signed between Israel and Egypt, Jordan, Lebanon, and Syria. Iraq gave the Samaria sector to Jordan and opposed any political contact with Israel. The borders agreed upon in the UN assembly on the 29th of November 1947, were broadened by a sizable measurement and a continuous territory was obtained. The cease-fire treaty stated that the cease-fire borderlines would be the armistice borderline, thus Israel lost control of the Old City in Jerusalem, the Etzion bloc, Atrot and Nevve Ya'akov in Northern Jerusalem, as well as Beit-Ha'arave in the Dead Sea area and Kfar Darom in the Gaza strip.