Heat oil in heavy medium skillet over medium heat. Add garlic and saute until golden brown, about 1 minute. Add tomato paste and stir 1 minute. Add clam juice, reserved 1/2 cup juice from clams and parsley and simmer until slightly thickened, about 15 minutes. Add clams and red pepper flakes and heat through. Season with salt and pepper. Pour sauce over fettuccine. Toss thoroughly and serve.