We are a week into the new U.S. policy seeking for Col. Muammar Qadhafi to leave power in Libya. And Libyans are another week into their bloody civil war, the future trajectory of which remains impossible to predict.Should Washington’s response to this crisis include the use of military force, and if so, how should it be done? A fierce debate has now erupted over the advisability of establishing a no-fly zone — with Defense Secretary Robert Gates the greatest apparent skeptic to date. Rather than focus on this alone, it may be more helpful to consider the full range of options, and the prospects for success of each.