The Soviet-Japanese pact signed 80 years ago today was part of Stalin’s plot that led to Pearl Harbor.

By Sean McMeekin

April 12, 2021


On April 13, 1941, Japan’s foreign minister, Yosuke Matsuoka, and the Soviet commissar of foreign affairs, Vyacheslav Molotov, signed a neutrality pact, valid for five years. Although less notorious than the 1939 Molotov-Ribbentrop Pact between the Soviets and the Nazis, which plunged Europe into war, the Soviet-Japanese neutrality pact had similar consequences in Asia.

As the London News Chronicle observed in reporting on the agreement: “What better guarantee [for Stalin] against Japanese hostility than Japan turning south and crossing swords with the United States? Moscow will feel secure in the Far East only when the Japanese and American navies engage.” Matsuoka and Stalin vowed Japan and the U.S.S.R. would “annihilate Anglo-Saxon ideology” and build a “new world order.” Matsuoka, a nationalist who signed the treaty with Japan’s Communist archenemy, later called Stalin’s neutrality pact an “act of diplomatic blitzkrieg.”

For years, there had been a tug-of-war in Tokyo between army and navy over strategy. The army’s “strike north” scheme envisioned a rapid conquest of Siberia to eliminate the Communist threat. Japan’s admirals, by contrast, war-gamed seizing resource-rich U.S. and European territories in Southeast Asia, in case Japan was ever cut off from American resources—especially oil—in retaliation for its 1937 invasion of China.

While many historians view the attack on Pearl Harbor as the inevitable outgrowth of U.S.-Japanese tensions, until April 1941 Japan’s factions remained in delicate balance, as did its relations with the Soviet Union, Britain and the U.S. Matsuoka’s brief on his European trip was to ascertain Hitler’s intentions: Would he invade Britain across the English Channel, or turn east and attack Soviet Russia?

Had Hitler told Matsuoka the truth and asked for help, it is likely that Japan would have attacked Siberia in coordination with Germany’s Operation Barbarossa, sparing Pearl Harbor. By refusing to trust Matsuoka, but letting Ribbentrop drop hints about his plans, Hitler gave Matsuoka motivation to betray him by agreeing to a deal with Stalin, almost out of spite. Matsuoka was drinking heavily with Stalin when he signed the neutrality pact and was still drunk when Stalin saw him off at the Moscow train station: Witnesses noted that Matsuoka “laughed with glee.”

There was nothing inevitable about the world-altering neutrality pact. Matsuoka, who had long opposed Soviet expansionism and favored the Axis, began to doubt what he had done once he sobered up. Stalin had charmed him into violating his own principles. After Hitler attacked Russia on June 22, 1941, Matsuoka advocated tearing up the neutrality pact and declaring war on the Soviets. After failing to convince the cabinet, in July 1941 he was forced to resign in disgrace.

By then the revolution in Japanese foreign policy was a fait accompli. To capitalize, Stalin activated his top asset in Washington, Assistant Treasury Secretary Harry Dexter White. White was enlisted in Operation Snow, a Soviet plot to get America to impose draconian export controls that would provoke

Japan into attacking the U.S. White was also the main author of the insulting “Hull note” handed to Japan’s ambassador on Nov. 26, 1941, which furnished Tokyo’s pretext for the Pearl Harbor attack.

Precisely as Stalin intended, the neutrality pact with Japan secured his Far Eastern frontier, just in time to save Moscow from the German onslaught in December 1941. Well-informed about deteriorating Japanese-American relations by his spy in the German Embassy in Tokyo, Richard Sorge, Stalin had begun transferring armor and troops from Siberia to his European fronts months earlier, in September 1941. Sorge, we now know, had advance knowledge of Japanese plans to attack U.S. and British positions in the Pacific once negotiations broke down—knowledge Stalin could have shared with Churchill and Roosevelt but didn’t.

Stalin withheld the intelligence from his accidental allies against Hitler because he wanted Japan to attack them. As he had told Matsuoka, “As for the Anglo-Saxons, Russians have never been friendly to them, and do not want now to befriend them.” Though in July 1941 Stalin had demanded from Roosevelt a pledge that Japanese “encroachments in Siberia not be tolerated,” when Roosevelt’s envoy asked Stalin that September whether the U.S. could count on Soviet help if hostilities developed with Japan, Stalin smiled and responded that “Russia might be neutral.”

Stalin was good to his word. Despite bellyaching about their Allies’ failure to open a “second front” against Hitler, the Soviets refused for four years to help them in any way against Japan. Stalin even interned as prisoners of war hundreds of American pilots who bailed out on Russian soil after bombing raids on Japan.

Japan took an indulgent attitude toward U.S. Lend-Lease vessels that ferried 8.24 million tons of war materiel through Japanese territorial waters to Vladivostok, Russia, between December 1941 and August 1945. Japanese admirals didn’t mind their American enemy wasting precious resources on the neutral U.S.S.R.

Unfortunately for Japan, Stalin was loyal only as long as he needed to be. After the U.S. dropped the first atomic bomb on Hiroshima on Aug. 6, 1945, Stalin ripped up the pact—nine months early—and invaded Japanese-occupied Manchuria and Korea. The invasion was supplied and fueled almost entirely by U.S. Lend-Lease aid. Softened up by four years of war waged by “Allies” whom Stalin refused to help, Japan had already transferred one million troops home from the Asian mainland, enabling the Red Army to conquer in a few weeks an area larger than France and Germany combined.

By encouraging Japan to attack the “Anglo-Saxon” powers instead of the U.S.S.R. in 1941, Stalin did pull off a diplomatic blitzkrieg. By supplying Stalin’s armies unconditionally despite Stalin’s refusal to join the war against Japan, Roosevelt helped Stalin plant the red flag in northern Asia, paving the way for Mao’s triumph in China and the enduring standoff in Korea. While hardly an anniversary to celebrate, April 13, 1941 was a day of infamy as consequential in Asia as Pearl Harbor.

Mr. McMeekin is a professor of history at Bard College and author of “Stalin’s War: A New History of World War II,” forthcoming April 20.