Webb appeared on "Fox News Sunday with Chris Wallace."
The senator, one of the principal critics of the Iraq war, said Democrats were not being "irresponsible" by calling for troop caps and withdrawals.
"I think what has been irresponsible has been the administration coming forward with solutions, or so-called solutions, that simply go back to the well again and again to the military without addressing the elephant in the bedroom," Webb said. "And the elephant in the bedroom is dealing with Iran and Syria."
He said he was not recommending "going to them on our knees or that we should be giving up on certain conditions," but, "I think there are reasons for them to come to the table" to help stabilize Iraq.
Iran directly participated in talks that led to the Karzai government in Afghanistan, Webb said, and "it is not in Syria's long-term interest to be an ally of Iran. Syria and Iran have never been natural allies. They're different ethnically. They're different politically."