Cook the spaghetti according to package directions. Drain; set aside.
Meanwhile, combine the croutons, 1/2 tablespoon of the parsley, and 1 tablespoon of the zest in a small bowl; set aside.
Heat the oil in a large nonstick skillet over medium heat. Add the shallot, garlic, and red pepper. Cook, stirring until the shallots are soft, about 1 minute. Add the shrimp and the salt, and cook, over medium-high heat, turning occasionally, until the shrimp are opaque, 1 to 2 minutes. Stir in the broth, wine, lemon juice, and olives. Bring to a boil and cook for 1 minute, then reduce the heat to medium. Stir in the spaghetti, the remaining 3 tablespoons parsley, and the remaining 1/2 tablespoon zest, tossing to coat well; remove from the heat.
Transfer to a large bowl. Sprinkle with the crouton mixture. Serve at once.
Nutritional analysis per serving:
Calories 330; Total Fat 8.5 g; (Sat Fat 1 g, Mono Fat 4 g, Poly Fat 1 g) ; Protein 26 g; Carb 35 g; Fiber 4 g; Cholesterol 130 mg; Sodium 400 mg