The United Nations Security Council authorized military strikes on Libya Thursday evening, and U.S. and European officials said air attacks against Col. Moammar Gadhafi's forces were possible "within hours."
The Pentagon was already fine-tuning military options for "serious" strikes against ground and air targets should the White House order them, said U.S. defense officials.
Options included using cruise missiles to take out fixed Libyan military sites and air-defense systems, according to these officials. Manned and unmanned aircraft could also be used against Col. Gadhafi's tanks, personnel carriers and infantry positions, with sorties being flown out of U.S. and North Atlantic Treaty Organization bases in the southern Mediterranean.
"There is significant, serious planning going on right now," a U.S. official said. The options would be "more aggressive than a show of force."