The U.S. could hit Syria with three days of missile strikes, perhaps beginning Thursday, in an attack meant more to send a message to Syrian President Bashar al-Assad than to topple him or cripple his military, senior U.S. officials told NBC News on Tuesday. “The options that we are considering are not about regime change,” White House press secretary Jay Carney told reporters at his daily briefing. Meanwhile, The Hill reports nearly two dozen House members have signed onto a letter demanding President Obama consult Congress —and wait for its authorization — before launching military strikes against Syria.