Wikipedia reports that is the Global Peace Index (GIP) is "now considered the benchmark study in measuring peace". This list attempts to measure (i) the level of safety and security in society, (ii) the extent of domestic and international conflict, and (iii) the degree of militarization. It ranks 162 countries, and has been produced annually since 2007. The 2014 list correlates pretty highly with GDP, though USA receives an intermediate ranking.
The 2015 GIP rates Syria, Afghanistan, South Sudan, and Iraq as the least peaceful nations, due to ongoing conflict. The nation most widely perceived as a threat to peace, the USA ranks 94 out of 162. This discrepancy is no doubt in part connected to the methodology of the index assignment. This makes broad use of fairly subjective assignments such as the "political terror scale" carried out by Western-backed institutions, such as the US State Department.
|John Lennon||“Peace is not something you wish for; it’s something you make, something you do, something you are and something you give away.”||John Lennon|
|Salmon Levinson||“The real disease of the world is the legality and availability of war. We should have, not as now, laws of war, but laws against war; just as there are no laws of murder or of poisoning, but laws against them.”||Salmon Levinson||August 1917|
|Love||“I refuse to accept the view that mankind is so tragically bound to the starless midnight of racism and war that the bright daybreak of peace and brotherhood can never become a reality… I believe that unarmed truth and unconditional love will have the final word.”||MLK|
|James R. Schlesinger||“Someone once said that war is hell, and peace is heaven. But we know that the opposite is true: War is heaven, and peace is hell.”||James R. Schlesinger|
|Howard Zinn||“They'll say we're disturbing the peace, but there is no peace. What really bothers them is we're disturbing the war.”||Howard Zinn|