In a large pot of boiling salted water, cook linguine, stirring often, until al dente, about 8 minutes. Drain thoroughly in a colander.
Heat oil in a deep skillet over medium heat. Add chopped onion and crushed red pepper and cook, stirring often, until softened, about 5 minutes. Stir in red wine and boil until syrupy, about 4 minutes. Stir in tomato sauce and clams with their juice and heat until simmering, about 10 minutes.
Add cooked pasta and parsley to clam sauce in skillet. Toss to coat pasta thoroughly.