"there are hundreds of incidents where governments did not have the interests of their own public at heart. They are not on the scale of Hiroshima, but they do exist. You should try reading up about them, it may change your mind on how benevolent governments are."
I'm well aware of the Tuskagee experiment. At the time it started, there was no effective treatment for syphilis and no likelihood that there would be, so it was not unethical. By about 1950, when penicillin was an effective treatment, the study should have been re-evaluated, but wasn't, and was clearly unethical after that point. It's not clear how many people knew about it - rather than your claim that this is "government", this was unethical behaviour at a local level. The behaviour of the CDC in the mid-1960s, when they became involved, was hideous, but it became public by 1972 and was torn apart by federal government. As soon as "government" knew about it, there were congressional hearings and massive compensation. That's not evil government doing systematic evil, that's a small group of racist doctors (the deep South in the 1930s) behaving badly and getting stopped fairly rapidly after news got out. Better it hadn't happened, but hardly proof that big government was being systematically evil.
The Pearl Harbour conspiracies are pretty much the same sort of confusing evil with sloth. Most of the investigations didn't have the power to get evidence from the NSA and its predecessors, and the claims of fore-knowledge rest on at the time undisclosed crypto capabilities (especially the early breaks into Purple). It's like the Burgess and Maclean theories, and the foolish decision to clear Philby in parliament: they were revealed by Venona, but at the time the project was still live and not likely to be disclosed. Purple didn't carry much about Pearl Harbour being attacked, and there is a lack of clarity about how much progress had been made against JN25 or how current the reading of the messages was.
In order to spark a war, the USN didn't need to risk its entire capability (the oil tanks at Pearl Harbour weren't hit; that was good fortune, and one or two stray bombs would have put the fleet out of action for months). All it needed to do was have a destroyer sunk or a few planes shot down, see Gulf of Tonkin twenty years later, if the intent was to enrange the US population.