Re-read the post. Nowhere does the author use the word pacifism.
Saying that a pacifist is "objectively pro-terrorist" is an awkward way of pointing out that pacifist policies will, in the judgment of a critic, assist terrorists. This simply reminds the audience that the pacifist view implies that even evil people can act with greater freedom from threat than would be possible under non-pacifist doctrines. This fact is obvious, however. It is a trivial implication of the pacifist doctrine. Calling pacifists "pro-terrorists" implies something further and unfair. It implies that pacifists support terrorism in some unseemly way-- yet the unseemliness of that support will depend entirely on the audience's rejecting pacifism.
Whether pacifism is true or false is precisely the question at issue when a critic charges that pacifism is "pro-terrorist". So, if one wants to impugn pacifism, one ought simply to say that the view is false and explain why. It is unfair to paint the view with a propagandistic taint without argument.
Pacifism is a false doctrine, in my view, since I do not believe it is morally required for those who wish to fight for good to permit even terrible evils to occur for fear of killing. It is not incumbent upon the innocent to suffer the evils of violence without recourse in preference to killing their tormentors. The rights which normally protect an evil-doer do not stand against attack in self-defense. In cases where there is much at stake, even innocent people may be killed to prevent still further evil. If, for example, it would have been possible to shoot down one of the airliners aimed at the WTC even if many dozens would have been killed on the ground that would be permissible, in my judgment.
At any rate, there is little to be gained in any discussion of pacifism by hurling charges of being "pro-terrorist".