The Korean War and the Division of Korea

In Korea the division is not an abstract backdrop; it is a practical condition. The northern boundary is a little over an hour by car from Seoul, and the top of the subway map ends at stations you cannot travel beyond.

This article is about how the line came to be drawn and why it did not come out, rather than about the war itself. Knowing the order of events changes what you are looking at from an observatory.

At a glance

The 38th parallel was 'military convenience'
After Japan's surrender in 1945 the peninsula was divided and occupied by US and Soviet forces at the 38th parallel for military convenience.
Independence came with a condition
The independence guaranteed at Cairo was conditional on being achieved 'in due course', and was reaffirmed at Potsdam.
Five years of trusteeship
In December 1945 at Moscow, the US, British and Soviet foreign ministers agreed on five years of trusteeship.
It is still an armistice
The armistice of 27 July 1953 halted the war, and that state of ceasefire still continues.

Independence was promised, with a condition attached

The division starts not in 1950 but in a sentence written in 1943.

The Cairo Declaration of December 1943 guaranteed the independence of Korea, and this was reaffirmed in the Potsdam Declaration of July 1945. But that independence was conditional on being achieved "in due course."

Other discussions were running in parallel. At Yalta in February 1945, a trusteeship made up of one representative each from the US, the USSR and China was raised, and on its duration the American side said 20 to 30 years was appropriate, based on the Philippines, while the Soviet side said the shorter the better — as recorded in American diplomatic documents.

In other words, the timing of Korea's independence was being negotiated in rooms where no Korean was present.

The line was drawn for 'military convenience'

This is the most commonly misunderstood point. The 38th parallel was not a border two Koreas agreed on.

When Japan surrendered on 15 August 1945, the peninsula it had governed was divided at the 38th parallel and occupied by US and Soviet forces, for military convenience.

The sequence bears that out. On 9 August the USSR declared war on Japan under the Yalta agreement, and began landing at Unggi and Najin on the 12th and at Cheongjin on the 14th, going on to occupy the whole area down to the 38th parallel; as soon as Japanese forces were disarmed, people's committees were organised and took on the shape of a government.

The encyclopedia records how Koreans understood it at the time: until the 38th parallel appeared, people thought the division would be temporary. That changed once they watched Soviet forces occupy the north and, shortly after, American forces occupy the south.

How a temporary line became a frontier

The five years that followed were decisive.

In December 1945 the US, British and Soviet foreign ministers met in Moscow and agreed to impose five years of trusteeship on the peninsula. In response Koreans mounted a fierce anti-trusteeship movement, but political confusion followed when left-wing forces, on Soviet instruction, switched to supporting it.

A US–Soviet Joint Commission met twice, in 1946 and 1947, and broke down without producing any solution.

The outcome sits in a single sentence. The 38th parallel, which had been a provisional military demarcation line drawn by the United States and the Soviet Union, became a border that was not a border, once North and South each established separate governments.

After liberation, separate governments were established in the north and the south within the Cold War system, and the war was fought on top of that.

Why it is still not 'over'

This is the question visitors ask most, and the answer is one line.

The armistice agreement of 27 July 1953 stopped the war. And the division subsequently became more entrenched, so that the state of ceasefire still continues.

"Stopped" and "ended" are different words. That is why a DMZ visit follows the procedures of entering a military area rather than those of visiting an attraction — identity checks, advance booking, and travel in designated vehicles.

Where you can look at the boundary

The places where the division is visible are not far from Seoul.

Imjingak can be reached without a separate military-control procedure, and the ribbons on its wire fence say what kind of place it is without a caption. The Third Infiltration Tunnel and Dora Observatory lie further in and have different access conditions.

Check how each of the three actually operates on its own page. Some sections can only be reached by shuttle, so a plan built around your own vehicle can stop at the gate.

Where the division is visible

Frequently asked questions

Why the 38th parallel in particular?

After Japan's surrender in 1945 the peninsula was divided at the 38th parallel and occupied by US and Soviet forces for military convenience. It was not a border agreed between two Koreas.

Was the division seen as permanent from the start?

No. Until the 38th parallel appeared, Koreans expected the division to be temporary. That changed once Soviet forces occupied the north and American forces the south.

What was the trusteeship plan?

In December 1945 the US, British and Soviet foreign ministers agreed in Moscow to impose five years of trusteeship on the peninsula. Koreans mounted a fierce movement against it.

Is the Korean War over?

The armistice of 27 July 1953 halted it. The division then became more entrenched, and the state of ceasefire still continues.

Can I just go to the DMZ?

Imjingak is relatively easy to reach, but the Third Infiltration Tunnel and Dora Observatory have different access conditions and some sections can only be reached by shuttle. Check each place's own page before planning.