TOKYO — The Japan Communist Party is the oldest political party in the country. It’s the largest nonruling Communist party in the world. It’s harshly critical of China. And the Japanese authorities list it, along with ISIS and North Korea, as a threat to national security.
To many in Japan, that comparison seems exaggerated. The party, which long ago abandoned Marx and Lenin and never really had time for Stalin or Mao, is about as radical as a beige cardigan: antiwar, pro-democracy, pro-economic equality.
But that hasn’t stopped it from becoming a primary target of Japan’s dominant political force, the Liberal Democratic Party, ahead of parliamentary elections on Sunday that will help set the country’s path out of the pandemic.
Though clocking in at only 3 percent support in the polls, the Communists have become a handy boogeyman after teaming up with Japan’s leading opposition parties for the first time in an effort to dethrone the L.D.P. The Communists agreed to withdraw their candidates from several districts to avoid splitting the liberal vote.
The conservative Liberal Democrats, who have governed almost continuously since the end of World War II, face little risk of losing power. But with their popularity sagging amid a weak economy and lingering questions over their handling of the coronavirus, they have tried to change the subject by painting the vote as a choice between democratic rule and Communist infiltration.
“The Communist Party’s strategy is to get one foot in the door,” Taro Kono, the L.D.P.’s public affairs chief, told voters during a campaign stop. “Then they wrench it open and take over the house,” he added.
The Japan Communist Party, founded in 1922, has long provoked government animosity. It vigorously opposed Japan’s military aggression before and during World War II, and the Japanese secret police persecuted and imprisoned Communists through the conflict’s end.
In the 1950s and ’60s, the Liberal Democrats — aided by the C.I.A. — carried out heavy-handed crackdowns on the group, which briefly flirted with political violence and became a rallying point for anti-American student protests.
Despite its name, the J.C.P. has largely abandoned its roots in favor of its own homegrown ideology. It broke with the Soviet Union and China in the 1960s and has recently become one of Beijing’s most vocal Japanese critics, denouncing its neighbor for following the path of “hegemony” and violating human rights in Hong Kong and Xinjiang. When the Chinese Communist Party celebrated its 100th anniversary this year, the J.C.P. was the only major Japanese party not to send congratulations.
Still, Japan’s National Police Agency has continued to treat the group as a menace. In its annual report on threats to the nation, it lumps the J.C.P. in with the Islamic State, North Korea and Aum Shinrikyo, the Japanese cult that killed 13 and injured thousands during a 1995 nerve-gas attack on the Tokyo subway.
The Japan Communists, the police note, are rapidly aging, losing their financial resources — mostly generated by subscriptions to their newspaper, Akahata, or Red Flag — and are having difficulty attracting…