Bring water to a boil in a medium saucepan; gradually stir in couscous and salt. Remove from heat; cover and let stand 5 minutes. Fluff with a fork.
While couscous stands, heat oil in a large nonstick skillet over medium-high heat. Add duck; cook 3 minutes on each side or until browned. Combine broth, wine, shallots, herbes de Provence, tomato paste, and cinnamon in a bowl, stirring with a whisk. Add broth mixture to pan. Cover, reduce heat, and simmer 3 minutes. Remove duck from pan; keep warm. Bring broth mixture to a boil; cook, uncovered, for 2 minutes. Stir in olives; cook 1 minute. Discard cinnamon stick. Spoon about 1/2 cup couscous onto each of 4 plates. Top each serving with 1 duck breast half and about 1/4 cup sauce.