A man looks at a billboard advertising the documentary film, "The Birth of Korea," at a movie theater in Seoul, Feb. 16. Newsis

Syngman Rhee was and still is one of the most hated South Koreans in North Korea.

As recently as last year, North Korea's state media disparaged the South as the "Rhee Syngman puppet group." This term dates back to the post-Korean War era, extending through the 1990s, when hate-filled banners targeting the first South Korean president were observed on the streets of Pyongyang.

That sentiment surprised Kim Deog-young, a documentary maker. He was intrigued by the obsessive hatred directed toward a leader who had passed away in 1965. This question prompted him to embark on a project to uncover the underlying reasons, and through his research, he eventually found the answer.

Kim, the director of "The Birth of Korea," a documentary film, explained that Rhee is despised by the North because he serves as a reminder of its failures. These failures include the inability to unite the Korean Peninsula under its communist rule and the failure to realize "utopian" visions for its own people. Rhee may have not seen the fruits of his visions for a free democratic state when he was alive, but many South Koreans today know and appreciate that he was right, the director added.

Kim Deog-young, director of "The Birth of Korea," a documentary film, speaks during its preview event in Seoul, Feb. 16. Yonhap

"We tend to take everything for granted and judge people in the past by today's standards," Kim told The Korea Times on Tuesday. "Take the Mutual Defense Treaty with the U.S. Other than Rhee, not a single politician supported it or thought that it would even be feasible. But Rhee knew South Korea would be doomed without that treaty."

Confronted with North Korea's communist army, supported by substantial forces from its allies in Russia and China, Rhee perceived the second invasion from the North as inevitable without a security guarantee from the United States. In a desperate attempt to prevent U.S. troops from withdrawing from the peninsula, Rhee released 25,000 prisoners of war, thereby disrupting negotiations for an armistice as he intended. This action greatly angered U.S. President Dwight Eisenhower, and Washington was so incensed that it even formulated a plan later to overthrow Rhee.

"When I was making the documentary film, I saw a leader trying everything possible to save his poor country," Kim said. "His endeavor humbles me and makes me realize that what we have as a country, such as freedom and safety, were not merely granted to us."

Kim emphasized that Rhee deserves significant credit for the mutual defense treaty alone because, without it, the remarkable achievements realized on the free land of South Korea might never have materialized.

That means there would have been no "miracle on the Han River," South Korea's rapid economic development, no companies like Samsung and no stars like BTS.

Under his leadership, South Korea also enacted the Land Reform Act, a measure economists say significantly reduced the influence of landlords and laid the foundation for its transition into a modern industrial country.

"I would put it this way. Park Chung-hee's train was able to run, thanks only to the railroad built by Rhee," Kim said in reference to the former president known for his great contribution to the nation's economic growth, who came to power three years after Rhee's resignation in 1960.

Yet for many decades, Rhee was vilified in South Korea as much as in the North as a symbol of an incompetent, self-serving leader. Lies and misinformation helped establish such negative images, some of which were debunked by this film. One of the most widely circulated fake stories is the allegation that Rhee fled while deceiving the public to secure time for himself, falsely claiming that South Korea was gaining the upper hand against Kim Il-sung's communist forces.

Decades after the war, South Korea emerged as an undisputed winner in the ideological war that once divided the world. The competition to create a more prosperous, admired society was over. The documentary film director said this might be the primary reason for much of North Korea's hatred of Rhee ― that he was right after all and Kim Il-sung was wrong.