Combine first 3 ingredients in a medium saucepan; bring to a boil. Cover, reduce heat, and simmer 40 minutes or until liquid is absorbed. Remove from heat, and let stand, covered, 5 minutes. Spoon rice mixture into a medium bowl. Add chickpeas, raisins, and green onions.
Combine vinegar and next 4 ingredients (through pepper) in a small bowl; stir with a whisk. Pour over barley mixture; toss well. Cover; chill 2 hours. Stir in basil and almonds.