In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].

Washington (CNN) -- "Our foreign policy is just spinning out of control" one senator said. "Recognize reality," chided another. Fourteen months after giving up his chairmanship of the Senate Foreign Relations Committee to become America's top diplomat, Secretary of State John Kerry faced harsh criticism Tuesday from the panel he used to lead. Some of it was the usual partisan sniping that permeates Washington, especially with congressional elections looming in November. However, Democrats also expressed concern about the U.S. response to Russia's tactics in Ukraine, negotiations on Iran's nuclear ambitions and the ongoing Syrian crisis. Kerry pushed back, at times accusing senators of uninformed or short-sighted assessments, and the sometimes sharp exchanges showed a rising skepticism in Congress for the policies and pronouncements of the Obama administration as it approaches the midpoint of a second term.Secretary of State Kerry gets a rough homecoming from his old Senate committeeDifficult diplomacy is "worth doing" even if it fails, Kerry saysRepublicans and some Democrats criticize U.S. foreign policy on Syria, Ukraine, IranSen. McCain tells Kerry to "recognize reality" about failing Middle East talks 
 Question:He took particular umbrage with complaints that Obama failed to attack _ for crossing the red line he set on using chemical weapons.
Syrian