1. In a large frying pan, heat the oil over moderately low heat. Add the garlic and cook, stirring, for 1 minute. Add the wine, thyme, and red-pepper flakes; bring to a simmer. Cook until reduced to about 1/3 cup, about 5 minutes.
2. Add the tomatoes, clam juice, and salt. Raise the heat to moderate and bring to a simmer. Cook, stirring occasionally, until thickened, about 10 minutes. Add the clams and bring back to a simmer. Continue simmering until the clams are just done, about 1 minute longer. Stir in the parsley and black pepper. Taste the sauce for salt, and add more if needed.
3. Meanwhile, in a large pot of boiling, salted water, cook the linguine until just done, about 12 minutes. Drain and toss with the sauce.
Test-Kitchen Tip: Chopped clams are good, but often the liquid they come in tastes of little more than salt. That's why we recommend draining the chopped clams and using bottled clam juice for the liquid in this dish.
Wine Recommendation: A chilled bottle of rosé, such as one from Provence in southern France or a dry California version, will be perfect with the saltiness of the clams and broth and the acidity of the tomato sauce. Avoid sweeter white zinfandels.