Heat a large heavy-bottomed pot over medium-high heat. Add the ground beef and cook, breaking it up with a spoon, until no longer pink.
Drain excess fat from the pot, leaving a little for sautéing the vegetables if desired.
Add the diced onion and diced green bell pepper to the pot and sauté until the onion is tender, about 5 minutes.
Add the minced garlic and cook for 30 seconds, stirring so it does not burn.
Stir in the tomato paste, tomato sauce, stewed tomatoes, Italian seasoning, Worcestershire sauce, sugar, salt, and water until well combined.
Bring the sauce to a simmer, then reduce heat to maintain a gentle simmer and cook, uncovered, for 30 minutes, stirring occasionally.
Taste and adjust seasoning if desired, then serve over cooked spaghetti or pasta of choice.