President Obama's remarks Thursday on the increasingly deadly standoff in Libya surely reflected the views of Americans who support Libyans' efforts to oust Moammar Gadhafi and join Tunisia and Egypt in the quest for freedom and democratic governance. But despite his robust demand to Gadhafi to "step down and leave" immediately, Washington's careful response to U.S. involvement remains muted.

There is good reason for that. Any effort to do something more dramatic, such as undertaking a military assault on Libya's air defense systems to establish a no-fly zone over Libya and suppress air attacks by Gadhafi's government forces on the rebels, would require an immense logistical, military and diplomatic commitment. It also would necessarily raise the issue of deeper involvement if the question then became whether to watch Libya tanks roll over civilians and massacre innocents to retain power. Would the United States help the rebels in ground battles? If Gadhafi ultimately defeats the rebels, would the United States then take on the fight - another war - to defeat Gadhafi head-on?

The level of force - ships, manpower, aircraft, refueling tankers and around-the-clock effort - needed to sustain just the preliminary initiative, a no-fly zone, could deeply enmesh the United States in armed conflict in another Muslim country. It alone could transform the nature of the grassroots Libyan uprising, inject the United States yet again in another Muslim country's internal affairs and siphon off vital resources from the already draining American-led conflicts in Afghanistan and Iraq.

That's neither a position, nor a mission, that the United States should seek except as a member of a well-coordinated and widely approved multinational military force. Such a mission would have to be supported by NATO or by a broader coalition. Yet, problematically, it would likely attract more resentment than support from other Middle Eastern Arab nations, most of which remain under the same sort of repressive, autocratic regimes that Libyan rebels are fighting to eject.

Defense Secretary Robert Gates has properly warned loose-talking members of Congress who advocate establishing a no-fly zone of the difficulties and ramifications of such an undertaking. Still, President Obama rightly expressed his intention Thursday to leave all options on the table. He acknowledged that contingency planning is under way to cover any alternatives that the situation may require, from a no-fly zone to a full-fledged response in the event of a humanitarian crisis.

He also has frozen all Libyan financial assets - over $32 billion so far - under U.S. jurisdiction. At this point, that's as much as he can do, at least publicly.

Other European countries have implemented freezes on the Gadhafi regime's assets, as well, and the Libyan dictator has been warned that he will be held accountable for human rights abuses and massacres.

That may be one reason why Gadhafi does not seem interested in fleeing his country. Most countries would not accept him now as an exile, and fewer still would want him without his ill-gotten wealth.

Gadhafi, instead, has ordered a brutal attempt to crush all opposition to his regime in Tripoli, and has had his military forces attempt to retake several cities that have fallen to the rebels.

At this juncture, it appears Gadhafi is willing to kill Libyan people indiscriminately to protect his hold on Tripoli, and that rebels in various cities, having raided military depots, are scrambling to organize and train themselves to resist more government attacks in rebel-held towns and villages.

The fighting could quickly shift from a stalemate to a stage of massacres. Libyan rebels need military aid, and fleeing civilians badly need assistance. The dilemma of whether, and how much, to aid the rebel fighters is dismaying, and it's not likely to end easily.