Congress is mulling how to proceed after President Barack Obama asked for congressional authority to train and equip moderate Syrian rebel forces in Saudi Arabia–with a $500 million price tag–to address the threat coming from the Islamic State of Iraq and Syria (ISIS). The Obama administration had already requested the $500 million as part of its fiscal year 2015 Overseas Contingency Operations budget. But with Congress unprepared to pass all its 12 spending bills before the Oct. 1 start of…