The US began deploying two Predator attack drones over the skies in Libya on Thursday.

Vice Chairman of the Joint Chiefs of Staff General James Cartwright told reporters, "The character of the fight has changed" because of NATO's efforts. 

He said Muammar Gaddafi's troops have dug in and the drones are needed to operate in urban areas and minimise collateral damage. But the rollout was dampened by bad weather.  They had to be recalled for the day.   

Secretary of Defence Robert Gates refused any notion of mission creep in Libya, saying, "The president has said that where we have some unique capabilities, he is willing to use those."  Gates went on to repeat what his boss, President Barack Obama, has said, that regime change comes best from within. 

The specters of Iraq and Vietnam loom large over US involvement in Libya.  In Vietnam, the US began by sending advisers in 1950 to help the South Vietnamese fight communist forces.  That gradually turned into a full scale war that lasted nearly a decade and left 58,000 US soldiers dead.

The drones now flying over Libya are remote piloted aircraft equipped with missiles to pinpoint targets.  And they're the same as the unpopular ones that patrol the skies over North and South Waziristan and occasionally miss their intended targets and hit civilians. 

But the Pentagon is optimistic about the success of the Libya mission, saying the Gaddafi regime is weakening because his military capability has been reduced and the embargoes and sanctions are effective. 

Gates admitted neither are short-term solutions and wouldn’t speculate on how long it might last.  To further help, the US authorised $25 million this week in non-lethal aid, including ambulances, binoculars, and fuel trucks.

That may not be what the American public wants to hear. A new ABC News poll shows the American public becoming increasingly polarized over what the US role should be in Libya.  Disapproval of Obama's handling of the conflict is up sharply from last month.  Now, 56% of Americans disapprove of US military involvement in Libya.  Of the 42% who approve of the job Obama's doing in Libya, most say the US should be working to oust Gaddafi. 

Members of the Obama administration continue to say that the US won't provide "boots on the ground" in Libya.  While US troops may not be an option, other NATO allies are sending trainers to help the Libyan opposition. 

Testifying before the Senate late last month, Gates said the opposition suffered from a lack of training and experience.  But when I asked him if the US is considering sending trainers, making contingency plans for sending trainers or if NATO had requested the US send trainers, Gates's response, "No, no, and no."