Most Peaceful Countries

Iceland is recovering from bankruptcy. At least three countries on this list have suffered recent terrorist attacks. Several have seen recent demonstrations on their streets which have turned violent. Australia has endemic racism. I have been to 16 out of 20 of these countries - most of them on many occasions. They are not exactly war zones but hardly the most peaceful places on Earth. On what basis are these more internally peaceful than any of the island nations in Australasia or places such ad St Vincent and St Kitts or Barbados? Malta is probably the most peaceful place I have ever been. Yet it doesn't make the cut. Please explain the basis of this selection and how you define 'peace' - lack of war? Tranquility? Quietness?