Obama's Arab Spring was what I was about to bring up. At the time, it was portrayed as such a great thing, and I even saw some college textbooks touting it as an example of how social media can be used to help improve society.

Now that the dust has settled, though, it was obviously a horrible thing. Even ignoring the Muslim Migration Crisis it helped trip off (which is terrible in and of itself, though many on the left tout it as a good thing), just look at the results in the Arab countries:

It spawned ISIS - enough said there.

Syrian civil war has been going on for over a decade now

Yemen still has a civil war ongoing too, with the US sill actively providing support to the Saudis intervening in it

Egypt had a military coup, and has been having Islamic groups launching occasional terror attacks to this day

In Libya, they kicked out Qaddafi (which, I'm increasingly convinced was the whole reason Obama and Killary instigated the Arab Spring), then had a half decade of civil war and still have violent protests going on

And probably more bad stuff in other countries. By any sane metric, the Arab Spring was a huge mistake.