I think we could if it was in fact specifically abhidhammic teachings that the Thai monks were using to support their ideas, and if they were reading and applying these teachings correctly. Having just read the book, I would say that this is not the case at all. The author (Bernard Faure) mistakenly treats the teaching that "kamma is cetanaa" (on which the Thai monks base their case) as if it were a uniquely abhidhammic doctrine, when in fact it's a core principle of both Sutta and Abhidhamma. As for the monks themselves, from the views that Faure attributes to them it's not at all evident that they have any acquaintance with the Abhidhamma. Faure writes:fragrant herbs wrote:I am reading the book, Buddhist Warfare. The use of the Abhidharma has been used by Thai monks to support the belief that they can kill. My question is, if Buddha in other texts says that it is wrong to go to war, such as this one below, can we then say that perhaps the Abhidharma is not Buddha's words?
"A related type of argument that is used by modern Thai and Sri Lankan monks (see Kent and Jerryson) is more psychological and seems to rely on the Abhidhamma. This argument emphasizes intention and claims that, if the killing is committed with the right state of mind (detachment or compassion), it entails no karmic consequence and therefore can be considered to be a wholesome act." (pp. 214)
But this is in plain contradiction to abhidhammic doctrines.
"...if the killing is committed with the right state of mind (detachment or compassion)..."
According to the Abhidhamma acts of intentional killing always proceed from aversion-rooted cittas. An aversion-rooted citta hardly qualifies as a "right state of mind". Moreover, since the mental factors of compassion (karu.naa) and detachment (alobha) never arise with aversion-rooted cittas, the authors are describing an impossibility.
"...it entails no karmic consequence..."
According to the Abhidhamma only an action that proceeds from the functional cittas of an arahant entails no kammic consequence. Any action proceeding from the kusala and akusala cittas of non-arahants is liable to generate a vipaaka.
"...and therefore can be considered to be a wholesome act..."
According to the Abhidhamma intentional killing can never be considered a wholesome act for it proceeds from an aversion-rooted citta and such cittas are always unwholesome.
Now the Abhidhamma does allow that a series of kusala cittas in which compassion is predominant may trigger a series of akusala cittas that impel a bad action of some kind. This would give us the kind of scenarios conventionally referred to as "doing evil with a good motive". For example stealing bread to feed the starving or having a sick pet euthanized. The point to note with such scenarios is that it is not the prior motive (or in abhidhammic terms, the preceding series of kusala cittas) that determines the moral tone of the action, kusala or akusala, but the akusala cittas that directly produce the action. The kusala prior motive will mitigate the degree of the akusala involved in the theft of the bread or the killing of the pet, but they don't have the power to transform the nature of these kammas from akusala into kusala.
For a detailed discussion of Abhidhamma and killing see Rupert Gethin's article Can Killing a Living Being Ever Be an Act of Compassion? The analysis of the act of killing in the Abhidhamma and Pali Commentaries
http://www.urbandharma.org/pdf/geth0401.pdf