Here’s a bit of info regarding both sides of this debate:
It is worth noting that the decision to create an independent Jewish homeland did not result from European guilt over the Nazi Holocaust as is sometimes claimed, but proceeded according to plans laid by Europe and the League of Nations after World War I for reorganizing the fragments of the shattered Ottoman Empire. These European plans also led to the creation of most of the other nation-states in the region.
On April 19, 1920, three years after the famous Balfour Declaration that established Britain's policy of favoring the establishment of Israel, representatives from Britain, France, Italy, Greece, Japan, and Belgium convened at San Remo in Italy to discuss a peace treaty with Turkey. It was decided under the authority of the League of Nations that Great Britain would be assigned the mandate over Palestine and shoulder the responsibility for implementing the pro-Zionist policy put forth in the the Balfour Declaration, in order to "[establish] in Palestine a national home for the Jewish people." Even before the conference had finished, however, Arab riots broke out in the territory, which prompted the Jews in turn to form the Haganah ("Defense"), a quasi-military organization.
In 1921, Britain separated 91,000 square kilometers (77%) of the Mandate and created the protectorate of Trans-Jordan, which later became the Arab country of Jordan. Throughout 1921, rioting in the remaining territory, known as Palestine, resulted in the deaths of 43 Jews. After several years of relative peace, riots again broke out in Jerusalem in 1929, sparked by anti-Jewish agitation during Friday prayers at the El Aqsa mosque where the Western or "Wailing" Wall is located. During the unrest, known to Arabs as the Al-Buraq Revolution after the Arabic name for the creature that supposedly carried Muhammad to Jerusalem, 133 Jews were killed in a single week, and 67 died in a massacre in Hebron. A large number of Arabs also died. The uncertainty among Jews about how to respond caused the Hanagah to split into an anti-military faction and a military faction led by Avraham Tehomi, the district commander of Jerusalem. Tehomi founded the "Irgun Zvai Le'umi" (National Military Organization), or ETZL, often spelled Etzel, also known as "Irgun B" or Haganah Le'umit (National Defense). While Hanagah had policy of self-restraint ('havlaga'), the Irgun adopted a more militant posture.
After the establishment of the New Zionist Organization in 1931, the Revisionist party, which had been formed in 1925 by Ze'ev Jabotinsky, seceded from the Histadrut party and founded the National Workers Association (Histadrut Ha'ovdim Hale'umit).
EARLY ZIONIST TERRORIST GANGS.
Soon after the end of World War II, there were three basic para-military Zionist organizations in Palestine, working against the Arab people, with the specific purpose of driving it out of Palestine. These were the Haganah, the Irgun Zvai Leumi and the Stern Gang.
Before the British Mandate, the Jewish settlers had formed a group of mounted armed watchmen called "Hashomar" and with the advent of the British Mandate, it became the Haganah (Defense). With a membership of 60,000 Zionist Jews, the Haganah had a field army of 16,000 trained men and a unit called the Palmach, which was a full-time force, numbering about 6000.
The Irgun Zvai Leumi included between 3000 and 5000 armed terrorists, and grew out of the Haganah and its Palmach branch in 1933. The Irgun was not ready to obey the Jewish Agency which sought to dilute the terror of the Haganah in order not to lose its respectability.
In 1939, one of Irgun's commanding officers, Abraham Stern, left the parent organization and formed the Stern Gang, numbering some 200 to 300 dangerous fanatics.
SOME EARLY EXAMPLES OF JEWISH-ZIONIST TERROR.
August 20, 1937 - June 29, 1939. During this period, the Zionists carried out a series of attacks against Arab buses, resulting in the death of 24 persons and wounding 25 others.
November 25, 1940. S.S.Patria was blown up by Jewish terrorists in Haifa harbour, killing 268 illegal Jewish immigrants (see below).
November 6, 1944. Zionist terrorists of the Stern Gang assassinated the British Minister Resident in the Middle East, Lord Moyne, in Cairo.
July 22, 1946. Zionist terrorists blew up the King David Hotel in Jerusalem, which housed the central offices of the civilian administration of the government of Palestine, killing or injuring more than 200 persons. The Irgun officially claimed responsibility for the incident, but subsequent evidence indicated that both the Haganah and the Jewish Agency were involved.
October 1, 1946. The British Embassy in Rome was badly damaged by bomb explosions, for which Irgun claimed responsibility.
June 1947. Letters sent to British Cabinet Ministers were found to contain bombs.
September 3, 1947. A postal bomb addressed to the British War Office exploded in the post office sorting room in London, injuring 2 persons. It was attributed to Irgun or Stern Gangs. (The Sunday Times, Sept. 24, 1972, p.8)
December ll, 1947. Six Arabs were killed and 30 wounded when bombs were thrown from Jewish trucks at Arab buses in Haifa; 12 Arabs were killed and others injured in an attack by armed Zionists on an Arab coastal village near Haifa.
December 13,1947. Zionist terrorists, believed to be members of Irgun Zvai Leumi, killed 18 Arabs and wounded nearly 60 in Jerusalem, Jaffa and Lydda areas. In Jerusalem, bombs were thrown in an Arab market-place near the Damascus Gate; in Jaffa, bombs were thrown into an Arab cafe; in the Arab village of Al Abbasya, near Lydda, 12 Arabs were killed in an attack with mortars and automatic weapons.
December 19, 1947. Haganah terrorists attacked an Arab village near Safad, blowing up two houses, in the ruins of which were found the bodies of 10 Arabs, including 5 children. Haganah admitted responsibility for the attack.
December 29, 1947. Two British constables and 11 Arabs were killed and 32 Arabs injured, at the Damascus Gate in Jerusalem when Irgun members threw a bomb from a taxi.
December 30,1947. A mixed force of the Zionist Palmach and the "Carmel Brigade" attacked the village of Balad al Sheikh, killing more than 60 Arabs.
1947 -- 1948. Over 700,000 Palestinian Arabs were uprooted from their homes and land, and forced to live in refugee camps on Israel's borders. They have been denied the right to return to their homes. They have been refused compensation for their homes, orchards, farms and other property stolen from them by the Israeli government. After their expulsion, the "Israeli Forces" totally obliterated (usually by bulldozing) 385 Arab villages and towns, out of a total of 475. Commonly, Israeli villages were built on the remaining rubble.
January 1, 1948. Haganah terrorists attacked a village on the slopes of Mount Carmel; 17 Arabs were killed and 33 wounded.
January 4, 1948. Haganah terrorists wearing British Army uniforms penetrated into the center of Jaffa and blew up the Serai (the old Turkish Government House) which was used as a headquarters of the Arab National Committee, killing more than 40 persons and wounding 98 others.
January 5, 1948. The Arab-owned Semiramis Hotel in Jerusalem was blown up, killing 20 persons, among them Viscount de Tapia, the Spanish Consul. Haganah admitted responsibility for this crime.
January 7, 1948. Seventeen Arabs were killed by a bomb at the Jaffa Gate in Jerusalem, 3 of them while trying to escape. Further casualties, including the murder of a British officer near Hebron, were reported from different parts of the country.
January 16, 1948. Zionists blew up three Arab buildings. In the first, 8 children between the ages of 18 months and 12 years, died.
December 13, 1947 -- February 10, 1948. Seven incidents of bomb-tossing at innocent Arab civilians in cafes and markets, killing 138 and wounding 271 others, During this period, there were 9 attacks on Arab buses. Zionists mined passenger trains on at least 4 occasions, killing 93 persons and wounding 161 others.
February 15, 1948. Haganah terrorists attacked an Arab village near Safad, blew up several houses, killing 11 Arabs, including 4 children..
March 3, 1948. Heavy damage was done to the Arab-owned Salam building in Haifa (a 7 story block of apartments and shops) by Zionists who drove an army lorry ( truck) up to the building and escaped before the detonation of 400 Ib. of explosives; casualties numbered 11 Arabs and 3 Armenians killed and 23 injured. The Stern Gang claimed responsibility for the incident.
March 22, 1948. A housing block in Iraq Street in Haifa was blown up killing 17 and injuring 100 others. Four members of the Stern Gang drove two truck-loads of explosives into the street and abandoned the vehicles before the explosion.
March 31, 1948. The Cairo-Haifa Express was mined, for the second time in a month, by an electronically-detonated land mine near Benyamina, killing 40 persons and wounding 60 others.
April 9, 1948. A combined force of Irgun Zvai Leumi and the Stern Gang, supported by the Palmach forces, captured the Arab village of Deir Yassin and killed more than 200 unarmed civilians, including countless women and children. Older men and young women were captured and paraded in chains in the Jewish Quarter of Jerusalem; 20 of the hostages were then shot in the quarry of Gevaat Shaul.
April 16, 1948. Zionists attacked the former British army camp at Tel Litvinsky, killing 90 Arabs there.
April 19, 1948. Fourteen Arabs were killed in a house in Tiberias, which was blown up by Zionist terrorists.
May 3, 1948. A book bomb addressed to a British Army officer, who had been stationed in Palestine exploded, killing his brother, Rex Farran.
May11, 1948. A letter bomb addressed to Sir Evelyn Barker, former Commanding Officer in Palestine, was detected in the nick of time by his wife.
April 25, 1948 -- May 13, 1948. Wholesale looting of Jaffa was carried out following armed attacks by Irgun and Haganah terrorists. They stripped and carried away everything they could, destroying what they could not take with them.
It was the dithering diplomats and bureaucrats who are primarily blamed for British failure here. Not knowing themselves what they wanted to achieve, they could hardly be expected to tell the army what to do next. Wildly jumping from appeasement of Arabs to Jews and back again left the army in a tenuous and ambiguous position. They lost a lot of credibility with both communities and lost the British as a whole a great deal of legitimacy in the mandate.
The next major problem was also somewhat out of the army's hands even if it did effect them directly. The demobilisation of the army after the Second World War led to a constant state of flux and confusion in all of the regular British Army units stationed there. This obviously meant that experienced men were leaving the service at an alarmlingly fast rate, meaning that they could not pass on their valuable skills and techniques to the newer arrivals. Many of the most innovative and successful practices were lost the army because of the speed of repatriation.
Of course, failure cannot be laid completely at the door of the British, it could always be argued that it wasn't the fact that the British failed so much as the Jews succeeded in their endeavours. There is no doubt that they were an extremely dedicated, skillful practitioners of guerilla warfare. The fact that all of the competing terrorist and political groupings managed to come together also helped them to project their power beyond their physical size.