I think various South Korean administrations have initiated such campaigns with evangelical Christianity. This has led to complaints by Buddihists of official and unofficial favoritism.
You mean South Korean presidents have identified the government with Christianity in the way that Saddam post-93 identified with Islam? I don't think so.
It is true that some(not a majority) of the schools in South Korea are run by evangelical groups(as well as Catholics), and people can be directed to send their chidren to those schools, but that's just more a matter of practicality, I think. The churches had experience doing that sort of thing from the missionary days, so they just got contracts to continue doing so.
I believe Rhee Syngmann was a devout Christian, but Park Chung Hee, who ruled between 1960 and 1979, was not(Jimmy Carter tried to convert him during a meeting in 1979 or so). As for the legitimately elected presidents, Lee Myung Bak in the 2000s was a hardcore evangelical, and did evince a pretty strong anti-Buddhist bias, eg. getting filmed at church services where Buddhism was denounced from the pulpit. But when his government began to show the beginnings of a sectarian tilt(I think the tourism department produced a map with temples omitted), there was a pretty severe backlash, and they quickly backed down.
And of course, Park Guen Hye(Chung Hee's daughter) was mixed up with that little Christian/shamanistic sect that eventually brought her down, but that wasn't anything that was promoted to the public.
All that said, protestant Christianity was indeed identified with the rising middle-class, and since the churches tended to be politically conservative, the government was probably happy enough for people to join, and probably allowed them a freer hand than was allowed the Buddhists(who I believe had their groups more strictly regulated). And the "mission schools" were allowed to require chapel attendance until a court ruling a few years ago.
But I don't think that was anything really like the active prosletyziation and identification of the state with faith, that took place in Iraq during Saddam's last decade in power.
TL/DR...
Protestant churches enjoyed a few privileges and a bit of political favour over the years, but nothing comparable to Saddam's Return To Faith campaign.