It's no suprise that the CIA might be linked to terror groups that even operated against the US's allies. Whilst many assume the US and UK have a long history of holding hands, the turth is they were very competitive between the Wars and after. The US has always had a particular fascination with reducing British influence in the Med, Mid-East and Asia, and the CIA is implicated in a number of anti-British activites that us Brits would view as terrorist. But at the time of the Irgun, Washington was much more interested in cultivating the Sauds as a balance to British influence in the Mid-East, so it is unlikley they were directly supporting the Irgun.
But the US does have a long history of what could be politely described as competing with the Empire. The US administration after the Great War was rabidly anti-colonial, the League of Nations being President Wilson's attempt to hamstring the European powers. That this later grew into the United Nations that today gives the US so much grief is ironic. Whilst supposedly friendly, the diplomatic rivalry between the US and the UK was particularly marked in view of the Royal Navy's superiority in warship numbers. One '20s dispute over a rock in the Pacific nearly led to naval action! Whilst the Washington Treaty probably stopped the UK going bankrupt, the limit on battleships and their size was the US's attempt to reduce the RN's power and hence Britain's influence abroad. In some ways it wasn't surprising that the FBI and Secret Service both ignored SIS warnings that the Japanese were going to attack Pearl Harbour. Instead, the CIA spent many years post-War strenuously denying that a British copy of the Russian spy Richard Sorge's report of the Jap plans had been hand-delivered to Washington in 1941.
Anti-British sentiment was also rife in parts of the US military right into the early years of WW2, USN's Admiral King's refusal to take advice on convoying from the Royal Navy being an example, leading to hundreds of sailors dying in U-boat attacks off the US coast. King's career didn't suffer, instead he was eventually promoted to be the first USN Fleet Admiral and tried his darnedest (but failed) to keep the Royal Navy out of any Allied activity in the Pacific.
It's not surprising that many up-and-coming American career diplomats picked up that anti-Empire sentiment in the '20s and carried it on into post-WW2 politics. The CIA was formed by those same diplomats post-War, from OSS men that had often competed with the British Secret Intelligence Service during WW2. The OSS often refused to share agents or information or listen to British warnings, and fed the rivalry between the Communist and non-Communist partisan groups in occupied Europe. Another prime case of US anglophobia occured in 1941 after the Italians broke into the US embassy in Rome and copied the US diplomatic codebook. The MI6 had warned Whitehall who warned the US that the embassy was not secure. The US Foreign Service had belatedly passed the warning to the US Secret Service who completely ignored it. The Italian break-in went undetected.
After this coup, the Italians wasted no time in sharing the code with the Nazis. At the time, the UK was seeking influence in Washington, and was allowing an US military attache, Colonel Fellers, complete freedom of action to explore the British frontlines in North Africa and even attend Auchinleck's staff meetings. Fellers was a champion of Lend Lease and seen as pro-British in a rather anti-British Washington, so Whitehall was anxious to ensure his support. Fellers, a very good officer, sent copious and accurate reports to Washington, and the Nazis read them all since the US was still using the same diplomatic codes that had been stolen by the Italians. What is more alarming is that those codes were very old, dating from many years pre-War, so should have been changed after Pearl Harbour anyway! The result was Erwin Rommel got almost daily reports of British dispositions, moral and intentions, and the SIS had to pussyfoot around Washington sensitivities when looking for the leak. The Desert Fox built his reputation in the Desert thanks to the US supplying him with all the information he needed.
Even when the SIS was sure Fellers was the unintentional leak, the British Government was wary about upsetting Washington, and so asked politley that they review security. The US response was tardy and led to further Commonwealth soldiers dying, all due to the US's Secret Service refusing to believe the SIS until it was too late. Post-War the leak was hushed up in the name of Allied unity, and Auchinleck's reputation was tarred as the General that couldn't stop Rommel. Auchinleck's replacement, Montgomery, arrived just after the leak had finally been plugged, and benefited immensely from the massive reduction in intel that was reaching Rommel, especially as RAF strength in North Africa had finally reached a point where Axis recce flights were being stopped. Amusingly, Monty wasn't much liked by the US either, especially after he later publically announced how he had saved the American bacon during the Battle of the Bulge, another dramatic US intelligence failure.
Post-WW2 the US and UK secret services were still at it in the Med, leading to mistrust and competition that allowed the Russians to dominate in Yugoslavia and almost gave them Greece and Italy as well. The British were quiet so as not to upset Washington and the new NATO alliance, but the majority of weapons captured from Cypriot terrorists/freedom-fighters in the '50s and '60s were of US origin. The SAS fighting rebels in the Gulf States in the same period often captured Saudis that had been trained by Americans in guerilla warfare techniques. There is some quiet discussion around the many geurilla units that set up post-WW2 in Asia, many of them having been cultivated by the US to fight the Japanese in WW2, but with suspicion that the CIA did not stop supporting them when they switched to fighting the Brits and the Dutch, even after it was obvious they were linked to Communist China. That this suspected unofficial policy of undermining European colonies later gave rise to America's own Domino nightmare is doubly ironic.
So, given the US's history of anti-colonialism, it's not surprising the CIA should be linked to attacks on what were often the prime targets of post-WW2 terrorists, namely European colonies. The surprise is that Wikileaks actually think this is newsworthy. If anything, it highlights the current US administration's over-concern with being seen as whiter-than-white and wanting to avoid using what could be construed as terror. Rather the opposite of what the usual CIA-bashers spew all over the Web. If this is the best of what Wikileaks are holding back then it's hard going to be hard to maintain interest, and harder still for them to drum up any more donations.