Afghanistan?

Jeffrey Goldberg, who blogs on the Atlantic Monthly online, writes this:

Sorry for saying this again, but I'm not clear about why Afghanistan is the
central front in the war on Islamist terror. Afghanistan did not produce the
terrorists who perpetrated the 9/11 attacks, nor did it have a central role in
the creation of the ideology of those terrorists (the Soviet defeat in
Afghanistan, of course, created feelings of superiority in Islamists, but that's
another story). It is an Arab-made ideology, and to a lesser though still
important degree, Pakistani-made, ideology that concerns us most. And it is Arab
and Pakistani terrorists who are our main concern. Obviously, the U.S. should be
in the business of denying safe havens to al-Qaeda terrorists in Afghanistan,
but occupying and reforming a country that has proven itself so resistant to
occupation and reform, and which isn't the at the root of the ideology we claim
we're fighting -- I'm not sure I get it. A more central front is Pakistan;
another more central front is Yemen. Cairo, London and Paris are also central
fronts. Iran is a central front of a different sort. And yes, Iraq is a central
front. But Afghanistan?