That is patently false. Publicly, the Yishuv was against underground organizations. Privately, there was much cooperation and coordination.
For example, Haganah handed Deir Yassin as a target to Irgun because they knew their fighters were ill-equipped to take on well-defended objectives. Indeed, they almost failed to capture the village so the Palmach had to come and help them quell the Arab resistance. The humiliated fighters took a bloody revenge on the Arab villagers. Afterwards, the Yishuv feigned outrage over the terrorist groups barbarism.
Later that year, Lehi murdered Folke Bernadotte. The Yishuv, again, feigned outrage and had many members arrested:
"Subsequently, many Stern members were disarmed and arrested, but nobody was charged with the killings, and the case, which was barely investigated, was closed. Stern suspects were detained after the assassination, but they were not treated like other prisoners. As Time magazine reported, these prisoners at Jaffa made their own rules, ripped bars from the windows and tore down the steel doors connecting their cells: “The Sternists threw open the door of the jail, disarmed the guards, directed traffic in the square where a great crowd had gathered. Some prisoners strolled off to the beach for a swim. Others relaxed with prison guards over coffee in a nearby café.”"
For example, Haganah handed Deir Yassin as a target to Irgun because they knew their fighters were ill-equipped to take on well-defended objectives. Indeed, they almost failed to capture the village so the Palmach had to come and help them quell the Arab resistance. The humiliated fighters took a bloody revenge on the Arab villagers. Afterwards, the Yishuv feigned outrage over the terrorist groups barbarism.
Later that year, Lehi murdered Folke Bernadotte. The Yishuv, again, feigned outrage and had many members arrested:
"Subsequently, many Stern members were disarmed and arrested, but nobody was charged with the killings, and the case, which was barely investigated, was closed. Stern suspects were detained after the assassination, but they were not treated like other prisoners. As Time magazine reported, these prisoners at Jaffa made their own rules, ripped bars from the windows and tore down the steel doors connecting their cells: “The Sternists threw open the door of the jail, disarmed the guards, directed traffic in the square where a great crowd had gathered. Some prisoners strolled off to the beach for a swim. Others relaxed with prison guards over coffee in a nearby café.”"
https://moderndiplomacy.eu/2025/04/05/the-demise-of-the-two-...
They were all pardoned a few months later.