The Cole-Goldberg "debate" is becoming increasingly one-sided, as you might expect in a battle between someone who is paid to think for a living (the Professor) and someone who is paid not to think (the Pundit). Goldberg is being made to look foolish, in part because he's sparring with someone who actually knows something about the subject, rather than someone who can write well and has a lot of opinions, but also due to the Elephant in the Room in the debate over the "War" on Terrorism: the Chickenhawk issue. The question to Goldberg was simple: can someone who is of age (or who has children of age) and who backs a discretionary war, ostensibly because it is in our national interest, have his views taken seriously if he (or his children) does not volunteer to fight in said war?
Obviously, this is a different issue than the standard "chickenhawk" debate, which concerns the disproportionate number of non-veterans in the Bush Administration. There may have been any number of reasons why someone didn't choose to fight in Vietnam, but few of them are germane four decades later. The issue at stake here is whether someone younger than, lets say, thirty-five (or with a son in that agegroup), has any moral or intellectual credibility to ask other people to make sacrifices for him, if he is not also willing to make the ultimate sacrifice.
It is, as "Armed Liberal" points out, a question designed to end debate. As well it should, for the issue is one of simple hypocrisy. No one should feel so privileged in a time of war to cheerlead from the sidelines, especially when one is healthy enough to play. If you believe it is important enough for your nation to be fighting this war, why aren't you out there?