Two months into his new post, South Korea's new consul general in Atlanta reminded business leaders on Monday that they were “on the cusp” of a new era in Korean-American relations.

Two days later, what He-beom Kim mentioned as a possibility has become a reality.

Despite fractious debate, South Korea's parliament passed a controversial free-trade agreement with the U.S. on Wednesday, a month after Congress overcame its own differences and passed the agreement ahead of Korean President Lee Myung-bak's visit to Washington in October.

The snap ...