The fighting at Lake Khasan begins

On 29 July 1938, in the fog at dawn, a Japanese detachment attacked a Soviet border post on Bezymyannaya Hill (Shachaofeng in Chinese and Japanese), west of the small Lake Khasan in the southernmost corner of Primorsky Krai. This stretch of the border was disputed: Japan and its puppet state of Manchukuo regarded both hills above the lake – Bezymyannaya and neighbouring Zaozyornaya (Changkufeng) – as Manchurian territory, while the USSR considered them its own. A handful of border guards lost the hill but retook it in the evening with the help of reinforcements. The clash, in itself one of hundreds of incidents on the border, opened a two-week battle involving tens of thousands of soldiers, tanks and aircraft. It was the first serious trial of strength between the Red Army and the Japanese army since the Siberian Intervention, and a foretaste of the even larger battle at Khalkhin Gol in 1939.

A border nobody had cared about

Ever since Manchukuo was created in 1932, Japan and the USSR had shared a border several thousand kilometres long: along the Amur, the Ussuri and the steppes of Mongolia. Its course had been fixed in the 19th century in treaties between Russia and the Qing dynasty, above all the Convention of Beijing of 1860. On many stretches it rested on old maps and sparsely placed boundary markers, which over time had fallen over or vanished. From the map attached to the convention and the Hunchun protocol of 1886, the Russians, and later the Soviets, concluded that the border ran along the crest of the hills west of Lake Khasan, across the summit of Zaozyornaya. The Japanese maintained that the whole ridge, right down to the lakeshore, belonged to Manchuria. As long as no one put posts there, the dispute was purely cartographic.

The terrain was unusual. Here, near the mouth of the Tumen River on the Sea of Japan, three states met: the USSR, Manchukuo and Korea, a Japanese colony since 1910. Between the river and the lake rose several bare hills about 150 metres high. Whoever sat on Zaozyornaya could see, on one side, the Soviet rear as far as Posyet Bay and, on the other, the Korean territory beyond the Tumen, the railway linking Korea with Manchuria and the approaches to the port of Rajin (today Rasŏn), which Japan was developing as one of the main gateways to Manchukuo. The Soviets, for their part, had only a single dirt road into this corner, running along a narrow strip between lakes and marshes. On the Japanese side this sector was the responsibility not of the Kwantung Army but of the Korean Army (Chōsen-gun) – specifically the 19th Division, based at Nanam (Japanese: Ranan) in northern Korea.

Border incidents began immediately after the Mukden incident and the conquest of Manchuria. According to Soviet figures, by the mid-1930s they numbered hundreds a year: patrols crossing the border, firing, abductions, clashes over river islands. In June 1937, a few weeks before the Marco Polo Bridge incident, there was a serious clash over islands in the Amur, during which Japanese artillery sank a Soviet gunboat and the Soviets eventually withdrew from the islands. Tokyo concluded that Moscow did not want war.

1938

After the outbreak of the Sino-Japanese War, relations between the two powers deteriorated further. Since 1936 Japan had been a party to the Anti-Comintern Pact with Germany, while on 21 August 1937 the USSR signed a non-aggression pact with Chiang Kai-shek’s China and began sending it arms, aircraft and volunteer airmen. The Japanese army feared that the Soviets would strike at Manchukuo at a convenient moment, when the main forces of the army were tied down in China. At the same time it knew that the Red Army was going through a period of profound weakness. The Great Purge had claimed Marshal Mikhail Tukhachevsky and a large part of the senior command, and in the Far East the arrests intensified in 1938. The details were supplied to the Japanese on 13 June 1938 (14 June according to some sources) by Genrikh Lyushkov, head of the NKVD in the Far East. Facing arrest, he crossed the border near Hunchun and betrayed to the Japanese the dispositions of the troops, the ciphers and the scale of the purges.

On 1 July 1938 the Special Red Banner Far Eastern Army was converted into the Far Eastern Front. It was commanded by Marshal Vasily Blyukher, a legend of the Civil War, in the 1920s a military adviser to Chiang Kai-shek and since 1929 the master of the Soviet Far East. The front’s chief of staff since shortly before was Grigory Shtern, who had returned from Spain, where he had been chief military adviser to the Republicans.

Border guards on Zaozyornaya

At the beginning of July the Soviet command decided to occupy the summit of Zaozyornaya, where until then no one had kept a post. According to the Japanese, an intercepted and decrypted report from Posyet recommended taking the unoccupied hills because of the view they gave over Korea and Rajin. Research in the Soviet archives after 1991 showed that the order was given orally on the initiative of the deputy head of the NKVD, Mikhail Frinovsky, who had come to the Far East to investigate the Lyushkov affair. Formally it was presented as a request from the commander of the 59th Posyet Border Detachment. On 8 and 9 July – or 11–12 July according to some sources – the border guards occupied the summit and began digging trenches and stringing barbed wire. Some of this work, as later Soviet findings showed, extended a few metres beyond the line that the Soviets themselves recognised as the border.

On 14 July Manchukuo protested, and on 15 July the Japanese chargé d’affaires in Moscow, followed by Ambassador Mamoru Shigemitsu, demanded the withdrawal of the border guards. The People’s Commissar for Foreign Affairs, Maxim Litvinov, produced the 1886 map and refused. During those same days a Japanese military policeman who had approached the Soviets to demand that the work stop was shot dead at the border by a Soviet soldier. On 20 July Shigemitsu repeated the demand in a form close to an ultimatum, and on 22 July the Soviet government rejected it.

In Tokyo the operations section of the General Staff, headed by Colonel Masazumi Inada, saw the situation as an opportunity. Inada believed that a limited strike at Zaozyornaya would be a “reconnaissance in force”: it would show whether the USSR was ready to go to war in defence of China and, at the same time, deter it from intervening before the planned offensive on Wuhan. General Kamezō Suetaka’s 19th Division was moved up to the border, and War Minister Seishirō Itagaki and the Chief of the General Staff, Prince Kotohito Kan’in, asked the Emperor for permission to use force. On 20 July Hirohito refused. According to the diary of Kumao Harada, secretary to the last genrō, Kinmochi Saionji, the Emperor rebuked Itagaki, reminding him of the army’s conduct at Mukden and at the Marco Polo Bridge, and declared that from then on not a single soldier was to be moved without his order. The General Staff instructed the Korean Army to remain in readiness but not to attack. Some Soviet and Russian publications claim that the Emperor approved the attack plan on 22 July; Japanese sources do not confirm this.

There was no unanimity on the Soviet side either. On 24 July Blyukher, without Moscow’s knowledge, sent a commission to Zaozyornaya, which found that in several places the border guards had crossed the border by a few metres. He ordered one of the trenches to be filled in and the barbed wire to be moved. In Moscow this was seen as undermining the government’s position, and the commission was held against Blyukher a few months later. That same day the front’s Military Council put the regiments of the 40th Rifle Division on alert, but they were stationed several dozen kilometres from the border, on the wrong side of the marshes.

29 July: Bezymyannaya

Bezymyannaya (Russian for “Nameless”) lies about two kilometres north of Zaozyornaya. On the morning of 29 July it was held by a patrol of a dozen or so border guards; Soviet sources speak of eleven men under Aleksei Makhalin, with one light machine gun. According to the Japanese version, the Soviets had just crossed the border at Shachaofeng and begun to dig in, and a Japanese border-security detachment attacked them on its own initiative, without orders from Tokyo. According to the Soviet version, the attack was planned in advance: some 150 soldiers and military policemen with four machine guns crept up to the hill in the fog and fell upon the post. The border guards held out for several hours; some of them were killed, Makhalin among them. The Japanese took the hill, but in the afternoon a reserve border-guard post and an infantry company from the 40th Division arrived and pushed them back beyond the ridge. By evening Soviet troops once again held Bezymyannaya.

Tokyo received the report of the fighting as a fait accompli. General Suetaka had instructions from his superiors to answer any further violation of the border with a “resolute counter-attack”, and he treated the retaking of Bezymyannaya as such a case. On the evening of 30 July Japanese artillery shelled both hills, and on the night of 30–31 July Colonel Kōtoku Satō’s 75th Infantry Regiment launched a night assault on both of them; according to Japanese sources, just over a thousand men attacked Zaozyornaya and fewer than four hundred Bezymyannaya, while Soviet sources speak of an attack by two regiments preceded by a short artillery bombardment. By the morning of 31 July Zaozyornaya and Bezymyannaya were in Japanese hands, and the Soviet units had fallen back beyond the lake. A local clash had turned into a battle, in which the next two weeks would decide who would give way.

Why it happened

Historians still argue over who really started the fighting at Lake Khasan. Soviet historiography presented it as Japanese aggression in which the Red Army defended the frontier of the USSR. In Japan it was called the “Changkufeng incident” (Chōkohō jiken) and described as the repulse of a Soviet incursion onto Manchukuo’s soil. Today it is known that both sides had a hand in it. It was the Soviets who, on the orders of the NKVD, occupied the disputed hill, which until then had belonged to no one, and they probably pushed their fortifications beyond the line they themselves recognised. It was the Japanese who attacked first, initially on 29 July and then with much larger forces on the night of 30–31 July, and their command in Tokyo had at least considered using the dispute to probe the strength of the Red Army. The most important book on the battle was written by the American historian Alvin D. Coox (The Anatomy of a Small War, 1977), who stressed that on both sides decisions were largely made by local commanders and services, while the governments tried to limit the fighting.

On the road to world war

The fighting at Lake Khasan ended after two weeks with a ceasefire and did not change the border. It nevertheless mattered for what came later. The Red Army, ravaged by the purges, displayed weaknesses of command that Moscow blamed on Marshal Blyukher; in the autumn of 1938 he was thrown into an NKVD prison and died under interrogation. The Japanese army, for its part, concluded that the Soviets did not want a war over Manchuria and ventured on the offensive against Wuhan, while the Kwantung Army ignored the lesson the Korean Army had been taught. A year later, at Khalkhin Gol in Mongolia, it began its own, much larger trial of strength and suffered a heavy defeat. That defeat, coinciding with the Molotov–Ribbentrop Pact, led Japan to turn south, towards the European colonies and war with the United States, and allowed the USSR to secure peace in the Far East until August 1945.