Iceland is the world's most peaceful nation while the United States is ranked among the bottom third, according to a study released today.
Australia slipped two places to be ranked only the 27th most peaceful out of 140 countries on the Global Peace Index, compiled by the Economist Intelligence Unit, while neighbour New Zealand is fourth.
Countries are ranked according to how peaceful they are domestically and how they interact with the outside world.
The United States slipped from 96th last year to 97th this year, but was still ahead of foe Iran which ranked 105th.
It, however, lagged Belarus, Cuba, South Korea, Chile, Libya and others which were listed as more peaceful.
Iraq, which the US invaded in 2003, leading to the toppling of Saddam Hussein, ranked lowest on the index. Afghanistan, another country invaded by the United States this decade, was also in the bottom five, along with Sudan, Somalia and Israel.
Commenting on the US ranking, State Department spokesman Sean McCormack said to realise a more peaceful and prosperous world, "Often times, you have to do difficult things and a lot of times, people don't agree with them. They don't like them."
"A lot of times you fall down in these lists but at the end of the day it is in defence of democracy and the way of life we have enjoyed over the past several decades," he added.
Small, stable and democratic countries were found to be the most peaceful in the index, with 16 of the top 20 coming from western or central European democracies.
The index looks at 24 indicators of external and internal measures of peace, including UN deployments overseas and levels of violent crime, respect for human rights, the number of soldiers killed overseas and arms sales.
The Group of Eight major economic powers were a mixed bag. Japan ranked fifth, Canada 11th, Germany 14th, Italy 28th, France 36th and Britain 49th.
Russia was near the bottom at 131st, the only one in the group below the United States.
The index was launched under the auspices of the Institute for Economics and Peace, a new think tank that looks at the relationship between economics, business and peace.
Supporters of the index urged policymakers to focus more on education, wealth, and well-functioning government and pointed to the role of business in creating more stability.
The 20 most peaceful countries, plus other nations of interest, Pacific countries, such as Fiji, were not included on the overall list:
1. Iceland
2. Denmark
3. Norway
4. New Zealand
5. Japan
6. Ireland
7. Portugal
8. Fiji
9. Luxembourg
10. Austria
11. Canada
12. Switzerland
13. Sweden
14. Germany
15. Belgium
16. Slovenia
17. Czech Republic
18. Hungary
19. Chile
20. Slovakia
23. Hong Kong
27. Australia
49. United Kingdom
67. China
68. Indonesia
95. Papua New Guinea
97. United States
107. India
124. Zimbabwe
131. Russia
132. Lebanon
136. Israel
137. Afghanistan
140. Iraq
