<img src=http://thecable.foreignpolicy.com/files/red_line_2.jpg width=425 height=269> A group of Syrian activists extended a long, symbolic red line in front of the White House Sunday in a call for the Obama administration to respond aggressively to the Syrian regime's alleged use of chemical weapons. The Syrian American Council, a U.S.-based group that supports the Syrian opposition, organized a series of events in the Washington area over the weekend and coordinated the White House protest. The group's sign, directed at President Barack Obama, reads "Your credibility is on the line." Obama gave no indication that his administration would change its calculus on whether or not to more aggressively support the armed Syrian opposition with lethal aid during his April 30 press conference. He did promise to continue to investigate what are now at least four instances of alleged chemical weapons use in Syria, two of which the U.S. intelligence community has said it can confirm, albeit with various degrees of confidence and with questions about who might be the perpetrator. "And what we now have is evidence that chemical weapons have been used inside of Syria, but we don't know how they were used, when they were used, who used them; we don't have chain of custody that establishes what exactly happened," Obama said. ""Obviously, there are options that are available to me that are on the shelf right now that we have not deployed, and that's a spectrum of options... And I won't go into the details of what those options might be." http://thecable.foreignpolicy.com/p...heir_own_red_line_in_front_of_the_white_house