The British government anticipated the threat of Jewish terrorism emanating outside Mandatory Palestine in the aftermath of the Second World War. The Irgun had been founded before the Holocaust out of discontent with the Haganah's policy of havlagah, or self-restraint. It became the armed wing of Revisionist Zionism in 1936, a turn related to the Arab recourse to insurrectionary violence in that year, itself a protest against British policy regarding Jewish immigration. Terrorism, the Irgun reasoned, was a winning tactic for it had enabled the Arabs to alter Great Britain's policy on Jewish migration into Palestine. The consequent White Paper of 1939 severely curtailed further Jewish immigration by imposing quotas and ignited a brief military response by the Irgun as well as its later offshoot Lehi, with both concluding that only campaigns of political violence targeting British personnel and installations could shift the British. The Irgun suspended these operations when the Second World War broke out some months later. News from occupied Europe of the Holocaust led them to undertake an insurrection in 1944 under the leadership of Menachem Begin. The Irgun also played a key role in organizing Aliyah Bet to enable clandestine Jewish immigration into Palestine, and is said to have singled out the Embassy convinced that it was a center of "anti Jewish intrigue" curbing illegal Jewish immigration to Palestine.