This is how you must train yourselves, monks.
Monks, as low-down thieves might carve one limb from limb with a double-handled saw, yet even then whoever sets his mind at enmity, he, for this reason, is not a doer of my teaching. Herein, monks, you should train yourselves thus:
‘Neither will our minds become perverted nor will we utter an evil speech, but kindly and compassionate will we dwell, with a mind of friendliness, void of hatred; and we will dwell having suffused that person with a mind of friendliness; and, beginning with him, we will dwell having suffused the whole world with a mind of friendliness that is far-reaching, widespread, immeasurable, without enmity, without malevolence.’
This is how you must train yourselves, monks.
MN21
If a monk acts agaist this teaching, then he is not a monk.
If a lay disciple of the Dhamma acts against this teaching, then he is not a lay disciple of the Dhamma.
Being a buddhist is not a title, it is an action. One may claim to be acting in the name of buddhism, but that does not make it so.
This conflicts are regretable to say the least, but they are not buddhist conflicts. They are created by the people who do not follow the teachings.
Therefore, Rev. Walpola Rahula’s statement is correct: no blood has ever been spilled at the hands of Buddhism.
This is just not possible, because the Dhamma protects itself from such actions. There are no exceptions, no footnotes or ‘ifs’. The Dhamma is clear in this aspect.
A ‘warrior monk’ is a contradiction in itself.
This does not mean that we should not be in the lookout for such mistakes and try to help avoid them and eliminate them. We should all always be open about this situations and be very clear about what the True Dhamma is.