I would hope NO state would do such a thing in the current time. We are well past the point in civilization to accept this type of action from any state or organization.
Pre 2001 a lot of people would claim that we are also against torture, extrajudicial kidnapping, secret trials, locking people up without trial, mass surveillance, and unprovoked wars. Things change.
Just as between WWII and the cold war people likely claimed "we'll never let stuff like what the Nazi's did happen again!" then the country(s) feel threatened and the gloves come off.
You can find lots of people after the Great Depression and the various responses arguing that the economic debates were settled and nobody would ever argue for unfettered investment banks and the like ever again. Meanwhile we got Alan Greenspan.
Per Wikipedia: "Historians have not fully agreed on the dates, but 1947–1991 is common" (WWII ended in 1945 for reference). But the cold war was a slowly building thing that took many more years to reach fruition.
So now that we've dealt with pedantic complaints that are wrong anyway, do you have any substantive problems with what I said?
The 1950s wasn't the dark ages. People in positions of power had already been through the horror of gas attacks in the First World War, which is about the closest equivalent. The Nazis had experimented with biological weapons, and this was reasonably widespread knowledge at the time.
So if your point is that it was a simpler, more ignorant time, I don't think that works.
What we all have to face is that, when allowed to operate in secret, this is what governments have done and will continue to do. Often with "good" intentions.
If there's something we need to evolve, it's the oversight of our institutions, or indeed abolishing some of them.
