Published: Jun 19, 2011 7:21 PM EDT
Updated: Jun 19, 2011 7:22 PM EDT

WASHINGTON (AP) - For legal reasons, President Barack Obama rejects the word "hostilities" to describe U.S. involvement in Libya's civil war. Along the same lines, Defense Secretary Robert Gates calls American actions there "a limited kinetic operation."
    
Definitions are part of the debate over whether Obama is violating the War Powers Resolution by failing to obtain congressional approval for U.S. participation in the NATO-led air strikes against Moammar Gadhafi's government.
    
The international coalition assisting Libyan rebels in their efforts to oust Gadhafi from power is in its fourth month. Before dawn on Sunday, NATO airstrikes began pounding targets in Tripoli as part of a stepped-up campaign.
    
The U.S. led airstrikes before turning over the mission to NATO forces. While no American troops are on the ground in Libya, the U.S. provides support with intelligence, reconnaissance and aerial refueling of warplanes. The Obama administration estimates the U.S. will spend more than $1 billion on the mission by early September.
    
Under the War Powers Resolution, passed by Congress in 1973, the president must seek lawmakers' approval to continue to engage in hostilities after 60 days and a 30-day extension.
    
Asked on "Fox News Sunday" if the U.S. was engaged in hostilities in Libya, Gates said: "The way I like to put it is, from our standpoint at the Pentagon, we're involved in a limited kinetic operation. If I'm in Gadhafi's palace, I suspect I think I'm at war."
    
The Obama administration argued in a report issued last week that the actions of the U.S. military in the NATO mission didn't rise to the level of hostilities as viewed under the law. House Speaker John Boehner, R-Ohio, was among the lawmakers who scoffed at that idea, saying it didn't pass the "straight-face test."
    
That Gates would support his commander in chief's view was not surprising. But the defense secretary apparently also wasn't backing the legal opinion of the Pentagon's own general counsel.
    
The New York Times has reported that top lawyers for the department of Defense and Justice told the administration that the resolution did apply to the mission in Libya. Instead, Obama accepted a different point of view, which was offered by his own White House counsel as well as other members of his legal team.
    
Gates, who is stepping down as defense secretary at the end of the month, said he would defer to Obama for legal definitions. But, he added, "I'm confident that he would not make judgment along these lines if he were not confident that he was acting in a constitutional manner."

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