Can 'Limited' U.S. Engagement In Libya Stay Limited?  The
Arleigh  Burke-class guided-missile destroyer USS Barry launches
a Tomahawk  cruise missile from the ships bow, off the Libyan
coast on March 29.   Jonathan Sunderman/U.S. Navy/AP  President
Obama's initial hopes that U.S. military action in Libya would
be over in a matter of "days, not weeks" have already been
dashed.  How long will it take?  There are many political forces
that make it difficult — once the U.S. military is involved
actively in another country — to pull out quickly.  "The notion
that you can put a toe in the water and not become more deeply
involved when you have the overwhelming resources in the region
seems sort of unlikely," says Micah Zenko, a fellow at the
Council on Foreign Relations.  The Obama administration has been
clear that there are limits to the amount and kind of resources
it is willing to devote to Libya. Defense Secretary Robert Gates
insisted in congressional testimony last week that no ground
troops would be sent th