WWII
I think if Pearl Harbor had not happened, the United States wouldn't have had a reason to jump into WW2 and not become a superpower. Hitler and the Axis were already being figured out and being dealt losses already by the time the US finally joined, so it was a matter of time before he was dealt with, it was only accelerated once the US joined.
Welp, anyone that they were originally going after is just wiping their foreheads in relief. Once this shitshow is over, they've long have gotten the time to cover whatever it is that they're doing, making it even harder to pin anyone down for what they did.
As far as recovering, yeah that's a good joke. We can forget about recovering, we'd need a big reset.