SEOUL, South Korea — Trying to catch up with Japan’s Nobel Prize count has long been something of an obsession in South Korea, but on Thursday a group of prominent Koreans started a signature-writing campaign to help Japan win another of the coveted prizes.

The move was not driven by a sudden welling up of warm feelings for Korea’s former colonial master. It was an attempt, instead, to keep Japan from any future aggression at a time when South Koreans are increasingly worried that Japan’s right-wing prime minister, Shinzo Abe, will create a more nationalistic Japan.

The South Koreans were offering support to a group of Japanese who campaigned to promote their Constitution’s Article 9, which renounces “war as a sovereign right,” as a nominee for the 2015 Nobel Peace Prize.

The group of South Koreans — about 50 dignitaries, including former prime ministers — hope that international recognition for Japan’s long-vaunted pacifism would forestall any efforts by Mr. Abe to water down the antiwar provisions in the Constitution.