Countering a two-year trend, the world overall became slightly more peaceful over the past year, according to an annual report released here on Tuesday.

The United States, however, moved down seven places to 88 out of 158, a “fairly low rank (that) largely reflects much higher levels of militarisation and involvement in external conflicts”, according to the Global Peace Index (GPI) 2012.

The report notes that although U.S. military expenditure “declined sharply” between 1991 and 2000, it “has now returned to Cold War levels”. Worryingly, the GPI finds that higher military expenditure (as a percentage of overall gross domestic product) correlates with lower levels of peace.

The U.S. also continues to score among the highest in the world on the proportion of its population in jail. (A U.S.-specific Peace Index was ...