838 Chapter 6
712 MONGOLIA/740 JAPANMID#182
Dispute Number: 182
Date(s): January 8, 1935 to March 31, 1936
Participants: 365 Russia, 712 Mongolia/740 Japan
Outcome (and Settlement): Yield by side A (None)
Fatalities: Missing
Narrative: Outer Mongolian troops clashed with Manchukuo and Japanese troops
along the border on several occasions. The Soviet Union demanded that Japan cease
its aggression against Outer Mongolia. Minor border clashes also occurred between
Japanese and Soviet troops on the Soviet-Manchukuo border.
Coding changes: Outcome changed from Yield by side A.
MID#258
Started in March 1939. See the narrative in the 255 Germany/290 Poland dyad dispute
list.
MID#183
Dispute Number: 183
Date(s): May 12, 1939 to September 16, 1939
Participants: 365 Russia, 712 Mongolia/740 Japan
Outcome (and Settlement): Victory for side A (Negotiated)
Fatalities: >999 deaths
Narrative: The border between Mongolia and Japanese-controlled Manchukuo was
both poorly defined and proximate to the Soviet border. Japan claimed the border
lay at the Khalkha River, while Mongolia’s claim extended 15 kilometers east to
Nomonhan. On May 12, 1939, Japanese soldiers attacked 700 Mongolian cavalry
who had entered the disputed territory. Clashes continued for weeks, each time lead-
ing to defeat for Japanese forces. At the end of May, Soviet forces joined the battles
with planes, tanks, and troops. The Chief of Staff of the Kwantung Army mobilized
all available forces to the fight, despite orders from Tokyo to avoid action that might
spread the war.
On June 27, 1939, 140 Japanese planes attacked inside Mongolia. The Soviets
and the Japanese then reinforced. On August 20, the Soviets launched an offensive
that inflicted 17,000 casualties on the Japanese. Tokyo initiated discussions with
Moscow on August 28, while the Kwantung Army sent fresh divisions to the front.
Tokyo and Moscow reached a truce on September 15, and fighting ceased the next
day. On November 19, the Soviets and Japanese agreed to establish a commission to
demarcate Manchukuo-Mongol border. The commission met several times through
January 20, 1940, but never came to a settlement. On June 9, Molotov and Togo
finally reached agreement on the general shape of the boundary, leaving the details
to a commission operating on the scene. Border demarcation finished May 15, 1942.