****Congress certainly has the power to pass a law ending a war. They can override a presidential veto.***
The ONLY power in ENDING a war that Congress has is in cutting off funding for it...
They must also vote to approve any peace treaties from that war...
If it simply ENDS, without a treaty, such as Korea, then Congress has no say in that decision...
Roberts just answered a question, and Leahy responded with "I hope you feel that way" -- in other words, questioning whether Robert's was truthfully answering the question.