It was just a pity that the government didn't want this sort of peace given by others.
They might have hesitated when they launched the nuclear missile, but it probably wasn't because they didn't want Superman to die; it was more likely they were afraid that he wouldn't die.
In any case, not many rich people had died at the hands of supervillains before Superman appeared; it was even less than what their own internal political conflicts caused.
Compared with the small chance of being out of luck, they wanted an Earth without Superman more.
That way, they would still be above everyone else, and wouldn't have to worry about being implicated by Superman.
Civilians who died at the hands of supervillains? That was nothing.