Prepare linguine according to package directions; drain. Keep warm.
Sauté garlic in hot oil in a large skillet over medium-high heat 1 to 2 minutes. Add clam juice and crushed red pepper; bring to a boil, reduce heat, and simmer 5 minutes. Stir in clams and next 4 ingredients; simmer 3 minutes. Toss with pasta and, if desired, 1 tablespoon butter. Serve immediately.