The withdrawal demonstrated to the South Koreans that the U.S. was not a credible ally and that if push comes to shove, it may actually betray South Korea as well.
In fact, there were attempts to pull out U.S. troops stationed in Korea by former Presidents Richard Nixon and Jimmy Carter. However, the bipartisan opposition of Congress and the U.S. national security establishment prevented a total pullout, which instead resulted in a reduction in the number of troops stationed here.
In the decades that followed, South Korea emerged as a vibrant democracy and one of the economic miracles of the 20th century.
These successes notwithstanding, 28,000 U.S. troops remain in South Korea today, at a cost of $3.5 billion annually to the American taxpayer, although it does not appear a further reduction in U.S. forces is likely anytime soon.
President Joe Biden was asked what the U.S. withdrawal from Afghanistan means for Washington's commitments elsewhere. Biden stressed the "fundamental difference" between Afghanistan and places like South Korea.
Yet the messy U.S. retreat from Afghanistan, and the ensuing Taliban takeover, has intensified questions about how much South Korea should depend on long term U.S. military protection, and whether Seoul should do more to look after its defense. Specifically, it may amplify the voices of those who want South Korea to pursue its own nuclear deterrent.
Doubts about the long-term U.S. military commitment were partly due to the experience of "America first" foreign policy of former President Donald Trump who, not only demanded South Korea pay an outrageous amount for the cost-sharing of U.S. troops, but also questioned whether the troops were necessary at all.
In addition, growing numbers on both sides of the U.S. electorate are skeptical of U.S. military involvement overseas.
Many Trump allied Republicans oppose what they call U.S. "forever wars." On the left, politicians such as Senator Bernie Sanders and Representative Alexandria Ocasio-Cortez, call for drastically reducing the Pentagon budget, along with a more restrained global agenda.
Thae Yong-ho, a former North Korean diplomat who defected to the South, and is now a lawmaker of the conservative People Power Party, said: "The lesson for us from the Afghan crisis is that there are no permanent enemies or permanent allies in this world. There is only national interest."
Another point of alliance tension is at what speed South Korea should regain control of its forces in the event of a war. In 1950, South Korea transferred command authority of its troops to the U.S.
Rep. Song Young-gil, the leader of the ruling Democratic Party of Korea, said the U.S. withdrawal from Afghanistan is the latest evidence Seoul should speed up the so called "OPCON transition."
The U.S. and South Korea agreed in 2018 to begin a three stage process to assess whether Seoul was ready to regain wartime control. U.S. officials warn against imposing a time limit, saying the transition should be conditions-based.
As the Taliban pushed from provincial capitals to Kabul, North Korea resumed its rhetoric against the presence of U.S. troops in South Korea as the allies engaged in their annual joint military exercises.
"For peace to settle on the peninsula, it is imperative for the U.S. to withdraw its aggression troops and war hardware deployed in South Korea," said Kim Yo-jong, the sister of North Korean leader Kim Jong-un, on Aug. 10.
North Korea's goal is to undermine the alliance and bring it to an end. And in recent years, the North Koreans have become much more active in trying to bring about this situation. This could be partly due to the accommodating attitude of the Moon Jae-in government towards North Korea.
During his address at the United Nations General Assembly, President Moon said that an official end to the Korean War would bring "irreversible progress in denuclearization and usher in an era of complete peace."
On Sept. 24, Kim Yo-jong called the prospect of an end-of-war declaration "an interesting and an admirable idea."
Her comments came several hours after North Korean Vice Foreign Minister Ri Thae-song said Moon's overture was "premature" and a potential smokescreen covering up the U.S. hostile policy, according to the Korean Central News Agency.
The contrasting remarks were intended for different audiences, Ri's meant mainly for the U.S. and Kim's aimed at Seoul.
Go Myung-hyun, a research fellow at Asan Institute for Policy Studies, said that Pyongyang is using a "divide-and-conquer" tactic between South Korea and the United States.
It's easily forgotten, especially by those who don't have firsthand experience, the desperate situation South Korea was in during the summer of 1950.
If the United States and the United Nations had not come to the rescue of South Korea, it is almost certain that today there would be no South Korea.
Indeed, we must be imaginative in our attempts to reach an agreement with North Korea to establish a permanent peace regime on the Korean peninsula.
At the same time, we must not forget that peace has been maintained for almost 70 years through the strong alliance between South Korea and the United States, and that the clear and present danger that a nuclear North Korea represents can only be resolved through close cooperation within the alliance.
Kim Sang-woo (swkim54@hotmail.com) is a former lawmaker and is currently chairman of the East Asia Cultural Project. He is also a member of the board of directors at the Kim Dae-jung Peace Foundation.