South Korea ranked 47th out of 162 countries on the 2013 Global Peace Index produced by the Institute of Economics and Peace, an Australia-based think tank.

It marked a 15-slot drop from 2007 when the index was first published, due to the growing nuclear threat from North Korea and historical rifts with Japan.

The annual survey is based on 22 indicators that also include crime, demonstrations, political instability and weapons trade.

Europe was found to be the most peaceable region with 13 countries in the top 20, while conflict-torn Afghanistan ranked last. The world has become 5 percent less peaceful since 2008, it said.

By Lee Sang-ju (sjlee370@heraldcorp.com)