WASHINGTON (AP) — Secretary of State John Kerry pushed back Tuesday against withering criticism by Republicans and some fellow Democrats, defending the Obama administration’s response to an emboldened Russia, nuclear talks with Iran and the Syrian civil war.

Defiant before the committee he once chaired, Kerry dismissed arguments that his globe-trotting attempts to broker a deal between the Israelis and Palestinians was a futile exercise and that the U.S. has been ineffective in ending the three-year civil war in Syria.