Question... was Ike’s meeting with Synghnam Rhee in Dec 52 a violation of the Logan Act? He was still a private citizen yet he discussed his plans for ending the Korean War with the Pres. of Souty Korea who did not approve of them. He likely shared these plans with leaders of the nations fighting with us and likely contacted leadership in the USSR as well.
Ike disagreed with Truman and Rhee and wanted to end the war. Ike had been briefed by Truman and Acheson before he went. Truman later called his visit a “piece of demagoguery” because Ike spoke his mind while he was there and met with our military leadership.
Regarding the Logan Act, Ike didn’t negotiate with Rhee, he met with him to learn of Rhee’s views and then sent Rhee a letter with Ike’s intentions.
So there was no negotiation or any agreements, just statements of opinion from both sides. Perfectly OK.
Check out: Harry and Ike: The Partnership That Remade the Postwar World, Steve Neal, 2002.