Cook spaghetti according to package directions. Drain and set aside to keep warm.
While spaghetti is cooking, in a sauté pan, or large skillet, using the oil over medium-high heat cook chicken until browned on all sides. Reduce heat to medium, add the onions, green pepper, and garlic, and continue cooking until vegetables are tender and chicken is done.
Stir the pasta sauce into the chicken mixture, add the wine, reduce heat to a high simmer and continue cooking until heated through and bubbly.