In any one particular case one can rationalize all sorts of excellent reasons...
It was you who started arguing about one particular case. Therefore my reaction logically addressed that case.
More generally, if you offer a particular event (siege of Kabul) as evidence for a general hypothesis (the US State Department always tries to utterly destroy the right enemies and never the left enemies), you have to show that the particular example really supports the general hypothesis (here you had to show that the reason of the SD’s opposition is best explained by sympathies to Taliban). But at this moment you can’t use the general hypothesis to show that it is indeed the best explanation; that would be circular.
It was you who started arguing about one particular case. Therefore my reaction logically addressed that case.
More generally, if you offer a particular event (siege of Kabul) as evidence for a general hypothesis (the US State Department always tries to utterly destroy the right enemies and never the left enemies), you have to show that the particular example really supports the general hypothesis (here you had to show that the reason of the SD’s opposition is best explained by sympathies to Taliban). But at this moment you can’t use the general hypothesis to show that it is indeed the best explanation; that would be circular.