“The historical significance of JUMPSEAT cannot be understated,” said Dr. James Outzen, NRO director of the Center for the Study of National Reconnaissance.
I'm no native speaker but that is backwards, right? Shouldn't it be overstated if it was a success?
Native here: you’re correct it’s a weird sentence and turn of phrase in English.
That said, can/cannot is a flexible word in English and we could take it to mean “Anyone discussing the significance of JUMPSEAT [accurately] [should never] understate it.”
But I think he meant overstate in this case. Or maybe he hated JUMPSEAT, thought it sucked and put that right out there in the press release.
I think so, "whatever you boast it's not overstating" -> cannot be overstated.